I found it hard to get rid of my childish self
I'm currently an adult ( for those wondering I'm 18 ) and I see myself acting 8 years younger than I really am and acting like a young child all the time. Coming out of my childish self was hard to do but all it took was a lot of incentive to say to myself " You are an adult, don't fool yourself ".
The last thing I ever did was let my childish self go, let it go into the wilderness where I won't see it ever again.