Grealish left boyhood club Aston Villa for a British record £100 million fee ahead of the 2021-2022 season as he joined Pep Guardiola's already impressive wealth of attacking riches.
The England international has since made his Champions League debut, scoring against RB Leipzig in September, while featuring regularly for City in the Premier League until suffering an injury on international duty with England earlier in November.
Grealish, who might be fit to face his former club on Thursday (AEDT), conceded the task of European football, and adapting to his new club, has been far more challenging than expected.
However, he in no way regrets his decision to swap Birmingham for Manchester.
"You only get one shot at your career and it just flies by," Grealish said. "I feel Villa are going towards that [Europe] but I just didn't know how long it was going to take for us.
"If I hadn't come here, I would have regretted it forever. I remember hearing Michael Owen say the same about Real Madrid.
"You look at most of my England team-mates – I was probably one of the last to play [in the] Champions League. You could probably count two or three who haven't, such as Kalvin Phillips or Sam Johnstone.
"It's the one we all want to win. The manager has come here and won everything else, we're all desperate to win it and I've come here to try and help them.
"I've got so much more to give. I've found it a lot more difficult than I thought I would, adapting to a different manager and team-mates.
"At first I thought I'd have more of the ball, get more assists and goals but it doesn't work like that at all. I've had nowhere near as much of the ball as I used to get at Villa."
Grealish has started in all of his nine appearances in the Premier League for City, who are a point behind leaders Chelsea after 13 games, but, as he explains himself, he is seeing less of the ball as a part of Guardiola's remarkable depth of attackers.
Grealish attempted 4.53 dribbles per 90 minutes in the league for Villa last term, which has reduced to 3.39 with City and this may have translated into his final output.
With Villa, he scored or assisted every 137 minutes, a figure that goes up to 248 this term with just one top-flight goal and two assists to his name.
He managed six goals and 10 assists in 26 appearances last season, creating 3.34 chances per match and shooting 2.06 times. Again, this falls to 3.15 for the former and 1.94 for the latter with the reigning champions.
Grealish also revealed he came close to joining City's neighbours Manchester United in 2020.
"I was really close to going, but nothing happened in the end," he said of the potential United transfer. "We played United in a pre-season game on [the] Saturday and I wasn't supposed to play in a cup game at Burton.
"But after the United game I said to [Christian] Purslow [Villa's chief executive] and my agent [David Manasseh] 'if I'm not leaving, I'll sign my new contract'.
"I went in with my dog on Tuesday morning, signed the deal, and played later that day. We all agreed on the clause and if any team hit that, it's a win-win because it means I've had an unbelievable season and Villa got £100 million."
Reiterating how difficult it was to move on from his former club, Grealish added: "You can't imagine how hard it was for me to leave.
"I was a bit surprised by some of the backlash when I left. I'd never want a toxic relationship with anyone there. I owe everything to them and I wouldn’t be at City without Villa.
"If I score, I'm not going to be celebrating. At the end of the day, I'm Jack Grealish from Solihull who loves the Villa."