In my experience, I find that any changes in myself have occurred naturally with age.
Comparing myself with how I was when I was 22, I'm 10 years older, have a lot less hair and am still maintaining my robust doughy physique, but I'm a lot more confident in myself.
Negative experiences have given me a slightly more toughened stance, a little bit more bullet proof. This occasionally comes across as confidence and as such women seem more receptive to it.
Having said all that, I am single with nothing on the horizon and if I met someone i really liked I will inevitably find an entirely new way to mess things up.