Forget achievement, it’s just greed in a socially acceptable form. You could spend your whole life worrying about how healthy you are, how interesting and how successful (whatever that means). As you may know, there’s a whole industry depending on our insecurities and our aspirations selling us products for self improvement, whether books, lectures or supplements, whatever.
But, you could instead simply focus on finding what you love, doing that and letting the success and self improvement come along for the ride. After all, writers write not because they enjoy all the typing but because they love words. Runners run not because the pain gives them a kick but because they love the miles passing beneath their feet. What’s your love?