"I just woke up," he tells reporters as he sits down, smoothie in hand. "I have an afternoon nap every day. I'm not the same man without it." And that man is someone English fans have taken to their hearts this summer, despite starting just once in the team's run to the Euro 2020 quarterfinals.
England fans at Wembley have sung his name -- "Super Jacky Grealish" -- in every game to date, even on three separate occasions when he was merely jogging along the touchline to loosen up, always ready to embrace the role of creator-in-chief.
Gareth Southgate's side have been extremely well-organised to date -- yet to concede a goal and winning three of four games -- but they have lacked a spark in the final third at times. It's the reason Grealish is in this squad: he's regularly provided it for Aston Villa to the extent that Premier League champions Manchester City are ready to part with £100 million so he can do it at the Etihad, too.
"At Villa, fans give me so much love: I go out there and try and repay them," he said on Thursday. "When I come here, it's different. I get booed every single week by these fans. When I watched [the World Cup] in 2018 in Russia, it was something that brought the nation together.
"When I speak to my Mum [Karen] and Dad [Kevin] they think it's so nice that people they are not going 'f--- him, if he was at Villa, we'd boo him every week.' They are all giving me that support, and doing it for the whole team."
England's relationship with their fans has transformed during Southgate's tenure because the players are encouraged to express who they really are. Grealish is one of the best in this regard, a reflection perhaps of his flair and flamboyance on the pitch.
"I don't know [why people connect with me]," he said. "I'm not too sure. I think it's purely because of what I am like on the pitch. I try and get fans off their seats. I try and attack as much as possible, and I think that's what fans want to see. I try and do as much as I can. I know what I am good at. I try and be as positive as possible all the time, no matter who I am coming up against.
"I have done this my whole life haven't I? I said [this] to my Dad earlier. He's a plasterer. I don't know if he's any good or not, but I said to him he had done it his whole life and so have I. Just because it's a bigger game or whatever, I don't really change anything I do. I do it every single day. I train every single day. Just because more people are watching or it's a bigger game, I don't really let that get to me. I just do it as though it's an under-18 match or a Villa game."
Grealish has maintained that mindset through comparisons with former England captain David Beckham -- the floppy hair and the No. 7 shirt practically invite them -- and Paul Gascoigne, the cheeky rascal who became the defining image of England's good times at Euro '96. Some players would disappear within the shadow of such greats, but this 25-year-old - with just 10 England caps to his name - embraces it, chiefly because he hasn't lost sight of who he would be if football hadn't transformed his life.
"I always try and play with a smile on my face because I'm doing what I love," he explains. "But then again, I think if I wasn't a footballer and I was just with my mates and stuff I would just be doing what they're doing. I'd be traveling everywhere watching England, being in pubs and stuff. I'd f---ing love it. I think I'd be at BoxPark [a chain of indoor entertainment venues with big screens showing matches]. I've seen a few videos of that and it looked unreal.
At the end of the day, I'm just a normal kid and as I've grown up [out] of it, that's probably one of the hardest things.
"I speak to my family about it all the time and stuff, because when I go out and do stuff, and I look at what my friends are doing -- I'd love to be like that sometimes, and just go and do stuff. "[If I hadn't been a footballer], I couldn't be a plasterer. Club promoter, [in] Tenerife. Or Ibiza. I would be getting everyone into the club."
Grealish is used to being made to wait for his England opportunity. Having switched his allegiance from the Republic of Ireland in 2015, the midfielder's senior debut only came in September 2020 during a 0-0 draw against Denmark in Copenhagen. The delays were a product of relegation with Villa a year later, off-field issues and a belated emergence into the match-winner he has since become.
The Villa star is pushing to start Saturday's quarterfinal against Ukraine in Rome -- particularly if Southgate abandons the 3-4-3 shape used to great effect against Germany -- but he recognises the competition for places in support of Harry Kane in attack.
"It is difficult: I'm always playing every single minute at Villa," he said. "I have to be realistic about myself and the talent that we have here, especially in my position. You have got six players that play either side of Harry that, in reality, could play for most clubs in the world. Myself, Jadon [Sancho], Marcus [Rashford], Raheem [Sterling], Phil Foden and Bukayo [Saka]. That's scary how good us six are. That's not being big-headed or nothing. That is just the truth.
"I've got to be realistic. I've just got to go and train as well as possible every single day and try and impress the manager as much as possible, because at the end of the day, there is only one person you have got to trust."
There has been a sense that he has had to win over Southgate, that perhaps a inherently conservative and supremely professional manager may have his doubts about a player like Grealish, a little rough around the edges with a mischievous streak. So how does Southgate show his love? "Plenty of cuddles!" Grealish jokes. "Nah, he's been perfect with me. I see some stuff sometimes about me and Gareth, but we have a great relationship and he does with all the players.
"That's one thing he does have. He's a brilliant man-manager and he has all these attacking players who play week in, week out at their clubs. It's the same for those who haven't had the game time they would have liked. He can't play all six of us. He can't play everyone. That's one thing he's done really well."
Grealish has been playing with a bandaged hand after breaking a finger in Villa's penultimate Premier League game of the season at Tottenham, but the bigger pre-tournament concern was the shin injury he sustained in February, which caused him to miss 12 Villa games, England's March internationals -- the final chance to impress Southgate in person before naming his Euros squad -- and still needed monitoring in the final weeks of the campaign, including England's Euro 2020 warm-up victories over Austria and Romania.
"They're feeling alright," he said. "When I had that pain, it was sore, man. When I got the ball at my feet, I'd forget about it a little bit but when I was tracking back I'd be thinking: 'f---ing hell.'
"I had it during January. We had a break when we had [a] COVID [outbreak] at the club and the youngsters had to play against Liverpool, and I had it then. Because I was in my house I was running on my treadmill and I don't know whether that helped. I don't think it did.
"The two games before my injury - the Brighton one away where we drew 0-0 and the week before when we beat Arsenal 1-0, it was agony. I had a scan and it was sore. I wasn't meant to come back as quickly as I did, but I felt I had to because everyone in my position was flying for England so I thought 'I need to get back here and show I'm fit and back to my normal self.' They feel good now."
His "normal self" is exactly what England fans have come to love about Grealish. "Deep down, I am still the Jack when I was young and I will never not be that person," he adds.
That comfort in his own skin is probably why he sleeps so well.