I think getting to understand our strengths and weaknesses is part of personal growth and becoming who we are.
For example, I used to think I was the greatest saleswoman on the face of the earth. When I realized that other women were routinely outselling me at work, I had to reevaluate that idea, and I took some sales courses. Now I am MUCH better at what I do, AND I still realize there is lots of room for improvement. So I still work at it.
In another example, I have really severe limitations in some aspects of my marriage. I tried for years to cope with things like jealousy, insecurity, trust, and similar things. I spent hours and hours in therapy trying to overcome these issues. I spent many nights crying over not being good enough/strong enough/brave enough/whatever. I am 40 years old now. I have been trying to deal with this stuff for more than 20 years. Finally I said to my husband, this is the way it is with me. I am stupid jealous and insecure. I can deal with X behavior, but not with Y. Z is grounds for divorce and it is non-negotiable. If you can do A, B, and C for me, I will be a much happier camper. In short, I have given up trying to fight certain limitations. Instead, I have changed the way I approached them and opened the door for discussion. It was the hardest thing to admit these things to myself, and even more so to explain to my husband which specific behaviors of his would really hurt me. But you know what? It was worth it. I don't spend any time trying to be someone I just am not, and he understands where my boundaries and limitations really are, instead of where I wish they were.
But sometimes I hurt myself, too. Trust does not come easily to me. I use this as an excuse not to reach out to people I would like to have for friends. I don't trust them; I don't trust my perceptions about whether they like me or are trustworthy or whatever. So why bother? I never trust anybody anyway, so how will I be their friend? I have been wrong so many times before, why should this be different? In short, knowing I have trust issues gives me an excuse not to try having any friendships, because I will probably just mess it up anyway.
So I would say that understanding your own issues can be a very helpful thing, so long as you either try to better yourself or set realistic expectations for yourself and don't (like me) use it as an excuse to limit yourself.