Is this whole "self development" thing actually working?

I've been trying to be a better person for a few years now, and having ups and downs but not really getting where i would like to be.

I feel like most successful people don't really have to go through that self development phase, they are just born that way and they grow up doing those things because that's just the way they are (talking to girls, working out, studying) not because they want to be "a better person".

For example studying, I've been working on my part time degree for a while now, and while I'm passing it so far I'm not really happy with the amount of knowledge that I'm absorbing, i find it hard to Focus on anything for more than 20 minutes.

I know it sounds a bit vague but hope you get my point? Some people just do things because they have always been like that, wheres when I'm doing things it's something that I wouldn't normally do and I label it as "self improvement".

I've seen green text picture from 4chan not so long ago, and it was describing this much better than I can