The 27-year-old completed his transfer to Stamford Bridge in a deal worth up to £50 million last month which ended his seven-year stay at City.
Sterling found himself on the bench for City's important matches last season including the Champions League semifinal clashes against Real Madrid, and the forward said he needed to leave for more minutes on the pitch.
"As a person, you strive to achieve," he told a news conference on Thursday. "I felt my playing time at City was being limited for different reasons and I couldn't afford to waste time. When I look back I didn't want to see a decline and I want to keep that level.
"Since the age of 17, I have been a regular starter. But to get to a peak time in my career to and be playing as regular was something I didn't want to accept. I tried to fight and change the scenario but it didn't come.
"At first, I had a few options but this was the one that was tailor-made for my personal goals. It made a lot of sense for my family and with the direction of the club. They have been in four or five finals in the last few years and it made a lot of sense.
"I have a lot of memories and top moments at City but in the year and a bit that I was in and out of the team it made me value a lot of things. It was difficult and my kids went to school there but it's one of those things in life where you have to make the right decision for yourself and your family."
Sterling enjoyed a successful Premier League debut for Chelsea last week after they secured a 1-0 win at Everton.
"It was nothing that played on my mind at all," he added. "I can't let an incident from individuals reflect on the club."
Sterling will face London rivals Tottenham in his home debut at Stamford Bridge on Sunday.