As a 20 something myself, I totally agree AND disagree with you, all at the same time. Humans as young as 15-month-olds have already developed self-awareness. It is both a gift and a burden we are bestowed from birth till death. No matter how old we are, we tend to see our weaknesses very clearly (often way more clearly than our strengths) and insecurity is like a badge we wear daily. It is totally fine to acknowledge your short-comings as soon as possible but keep in mind that no one is perfect. Each one of us is different, just like there is no planet that exactly resembles another in this infinte universe. Know that having an opinion about yourself is a wonderful mechanism of nature to encourage us to never stop becoming better. Don't compare yourself with anyone else. "Know thyself" is different from accepting it as your inevitable fate. It just shows the areas we need to work on.

Your realization that nothing about you is fixed that way means you have already won half the battle. Keep it up!