I was a selfish narcissistic young man
How old were you when you felt this way?
I was in college, It's totally normal to be selfish at the age of 23.
A lot of people are selfish when they are 23. The important thing is that you continue to grow and you aren't selfish now.
I will try to be better and be less selfish.
It is good that you are acknowledging how you were acting, these feeling were normal for someone of that age. As long as you learn and grow while you age, then it is okay.