It's tough to be wired as an optimizer
People like him are horrid traps for optimisers. They’re pointing out errors, and being so desperate to improve you’re encouraged to keep listening and value them greater instead of tuning their overeagerness out.
There’s an irony that actually getting hung up on minor comments and suggestions is in itself poor optimisation since the error becomes a distraction instead of a learning point.
(Having said that, restarting a game over and over in order to force your one perfect linear optimal plan to eventually work out can be lots of fun. But this is not an option in real life.)
While I'm on the cheesy aphorisms, I'll throw in "life is what happens while you're busy making other plans". But that one's too pragmatic, I think. It's not as if we have zero control. Maybe a more accurate statement would be "life is what happens while you're busy making loosely similar plans".
It is possible to lessen the effect of these things if you put effort into it.