The 20-year-old winger spent the 2013/14 campaign at Goodison Park as parent club Barcelona sought to get important experience under his belt.
The youngster showed glimpses of what he is capable of in England, making 29 appearances in all competitions and netting four goals.
Deulofeu now feels better prepared to compete for first-team recognition at the Nou Camp, but still believes that Roberto Martinez could have got more out of him on Merseyside.
He said in the Liverpool Echo: “Until you so somewhere else you don’t know what you’ve got.
“I’m glad I spent a year at Everton. I learned a lot of things. It was a good experience for me and I have improved in terms of fitness, the physical side and defending.
“I really enjoyed it at Everton, but I am left with the feeling of having played a few minutes.
“I still think I deserved to play more, although my mid-season injury had an impact.”
Everton had been hoping to bring Deulofeu back for a second spell, but his focus is locked on making the breakthrough into a star-studded Barcelona side.
He added: “Coming home was always my objective.
“I am confident I can establish myself in the team, because if I wasn’t, then I wouldn’t be here.
“I know that Barca has the best footballers but I am confident in myself and have high hopes of winning myself a place.
“If I don’t work hard enough, then other players will play instead of me. (Lionel) Messi, Neymar and (Luis) Suarez are three of the best players in the world, but we still have to prove that we have the best forward line in the world.
“The coach won’t be giving away places for free, we all have to work. I am looking forward to learning from them.”