Do you ever feel like you lost a match but don’t know the real reason?

I'm an NTRP 4.5 player, and I've recently lost several matches against weaker players. In my opinion, they had worse technique and worse physical form. So I'm pretty sure I could beat them 9/10 times.

I can only guess that I got mentally tight and everything broke down: footwork, proper technique, etc.

But instead of guessing, I'm wondering, for people who play 2–5x/week: what do you wish you could know after a match that you currently don’t get from a watch, coach, SwingVision, or match stats?