James Corden saw a therapist because he was worried he was becoming a "d**k".
The 32-year-old actor has undertaken 18 months of therapy following a period of hard partying, and he would "recommend" anyone to do it.
He said: "It's just sitting talking to someone, but when you say things out loud you think more about how you've been behaving at certain times.
"I was aware that perhaps I was becoming a bit of a d**k. Therapy is nice. I'd recommend it to anyone. It has been beneficial to be being happier, and a better boyfriend, and a better friend.
"I'm just grateful that I was able to sort of wake up in enough time."
The former 'Gavin and Stacey' star recently welcomed first son Max with fiancee Julia Carey, who he credits with being "really nice" to him.
He added to The Sunday Times Magazine: "She's the best thing that's happened to me.
"She just really nice to me. The truth is, all that time I was going out it was only ever to look for someone I could stay with."