When you’ve been doing something for a few years. You’ve developed and identity around it, as if it was part of you. Learning that there’s something that could have been done differently even though is basically just constructive criticism. Might appear an attack on that identity. The problem here is your ego.
Did you ever notice the beginners Are often able to find Solutions for things the professionals haven’t been able to find for years? The reason for that is they don’t know all the things that aren’t going to work. They’re just trying it for the first time, and as beginners their ego is not at stake.
Next time you’re facing a difficult issue. Try to forget all the things you know aren’t going to work and attack the issue as if you’re doing it for the first time. Allow yourself to make mistakes, your ego might get bruised but so what. The important thing is you get the job done.