Great question. I have been very active with self improvement for 3.5 years now (started it when I quit gaming). I was able to develop a lot, at age 26 I used to be a (to be completely frank) loser. I was living with my mom, college dropout, addicted to video games, virgin, very shy, very low confidence, not athletic. Since then I was able to progress in all the mentioned areas. Move out, get a girlfriend, get in shape, have a decent career, learn basic social skills, think higher of myself. This sounds like it would be all amazing, but you have a point, I am often stressed about bettering the next part of my life, feel unsatisfied with the levels I achieved in the named areas. My goals have shifted now I want: High confidence, world class career, women at my feet, great social skills.
I think this is normal human behaviour, you always crave the next thing. I now look at the future and all the work I have to put in and all the years it will take to work on these goals.
So I am both very excited and definitely more content with my situation but I also woke up to the potential of where I can go, which I just didn't realize before and that sometimes can be a burden, or maybe I just haven't found the right angle yet to look at it to relieve that burden.
I do have a lot more happy days though