One of the driving forces of my life is the need to constantly improve myself. I am NEVER satisfied with anything I do. I'm always feeling inadequate and pressured to perform better. It's 100 % or nothing. 
A friend told me that feelings of inadequacy and pressure are typically rooted in childhood experiences. I'm from a family of sports and was basically raised to be a competitor. My brain has a tendency to mix up You can always do better and you can always learn and grow with It's not enough and it will probably never be enough. 
"Ok. You might have achieved a million other goals, but do you have perfect skin? Can you recite Shakespeare? Can you run 20 kms instead of only 10 kms? Do I look weird from that angle? Can you read 5 books a month like you used to do when you were a teenager?" - My brain. (Just like that Shania Twain's 90's hit. But minus the guy who thinks he's Brad Pitt or owns an impressing car or whatever. Lol. And the cat suit. The suit is pretty awesome though) 
I'm certain that I'm not the only one when I say that alot of people are never adequate, never good enough, never self-confident, never perfect, never comfortable with ourselves, never satisfied, never really content. Or as content as we want to feel. As content as we think we need feel to accept ourselves.
It doesn't matter if I have achieved a thousand other goals. I'm always left feeling unfulfilled. I'm not saying that I'm always grasping for outside validation. I've never really been one to care about external attention or what others might think about me. Well, to be honest I really don't give a shit. It's always been about myself and my own thoughts about myself. 
I used to be obsessed with Meg Cabot's "Princess Diaries" book series in my tween toteenager years. (Those books are brilliant by the way. I was re-reading them two years ago and I couldn't stop howling. It has too many genius pop-cultural references and if you know me, you also know that I live for pop-cultural references) - and the lead character, Mia was always talking about reaching self actualization = Living to your true potential. 
I've come to accept that this is me and probably always will be the way I think.