Ross Barkley says his decision to leave boyhood club Everton for Chelsea has helped him mature as a "person and a player".
Barkley arrived at Stamford Bridge in January 2018 but was restricted to only a handful of appearances in his first campaign due to a series of injuries.
He has been in fine form this season, though, making 39 appearances across all competitions for Maurizio Sarri's side.
He demonstrated his progress on Monday, scoring twice in England's 5-1 Euro 2020 qualifying win over Montenegro, and the 25-year-old attributes his new-found confidence to leaving his comfort zone in Merseyside.
"Yes, exactly," Barkley told reporters when asked if he needed the move.
"I am away from my family and down in London by myself. I am in a totally different environment from Liverpool. I miss being with my family, it is totally different. It is how I am maturing as a person and a player. It is good.
"Since I made the move it was good to challenge myself and win trophies and to improve as a player. I've changed compared to when I was 18, 19 or 20.
"My diet is much better. My approach to games is much better and I am going into them with the right preparation and I am more relaxed, rather than thinking about things too much."
Barkley says his performance against Montenegro was his best in an England shirt, but insists there is still room for improvement.
"It was my best performance for England," he added. "I came up with the two goals and had a hand in a couple of the goals, but I felt I could have played better.
"We can all improve. We are not in the game to accept where we are at. We have to improve at club level and at international level – there is a lot of room for improvement.
"I never thought I would not play for my country. We all go through difficult spells. But I am just believing in myself now and having confidence."