The 27-year-old spent time out of City's XI during the club's Premier League winning campaign, after a series of high-profile mistakes.
However, Hart quickly reclaimed his place in Manuel Pellegrini's starting line-up, and made 31 appearances in the top flight last term.
Hart believes he has learned valuable lessons from the experience, and has vowed to keep improving.
"I was just focused on getting back in the team at Man City to be honest," he said.
"I've learned it's a long season and it definitely doesn't just revolve around myself. There are some great goalkeepers around the world, and we have two besides me at a great club like Manchester City.
"I just knew I had to work hard and try to get to the best level I can be, and that's no different now. And I want to give the best options for the manager.
"I'm living in the moment, I'm enjoying things. When I was out of the side I worked hard to try to get back in. I tried to do my best and that's the same now.
"I'm constantly trying to improve, still trying to cling on to being a young guy. I'm trying to improve daily so I'd like to think I'm in a better place than I was four years ago, for the experiences in that time.
"I want to keep improving. The day I stop trying to improve is the day that I finish. Hopefully I'll be going on that track for a good while yet."
Hart - who was a member of England's ill-fated 2010 World Cup campaign in South Africa - is in confident mood ahead of the June 14 opener with Italy, while also stating his belief that individual club form will have no bearing on England's campaign in Brazil.
He added: "As soon as we've come into England mode, what happened with the club season doesn't really affect things.
"There's a great feel-good factor heading into a World Cup, whatever happened in the season for any of the lads.
"It's full of England players who want to do well for their country, and it's pretty similar to four years ago in that respect.
"We all want to go out and represent our country as well as we can, represent the people, and it's been like that for years.
"I feel good, the team feels good, we're defending well, we're getting our principles right, listening to the manager and the coaches, and things are going well."
