There will be things you never quite mastered, skills you never perfected, and stuff that you didn’t get around to doing. No human is without flaws and you’ll always see someone who can do or has done something that you haven’t, can’t or won’t.
The best any of us mortals can do is constant improvement. Always seeking ways to make ourselves better and make the things we get involved with better for having had us involved. The idea, or theme, of improvement can be done by anyone; perfection can be done by no one. Aiming for improvement sets you up for success; aiming for perfection sets you up to be disappointed since no human is perfect.
Focus on continuing to get better, because it gives you something to do. Perfection is an endpoint, and since life is always moving forward, where would you go from there?