You can always look back and see where you might have done something differently, changed this or that. If you can learn something, fine, but never second-guess yourself. It's wasted effort.
Things don't always work out. Does worrying about it, complaining about it, change it? Nope it just wastes your time. And if you complain about it to other people, you're also wasting their time.
Nothing is gained by wasting all of that time.
Notes from Coach John Wooden