Does anybody here feel like they’ve PURELY wasted so much time and effort, without any reason to come from it. How do you not let it haunt you?

I’m talking about genuinely pure wasted time and effort. Zero beneficial gain, no lesson, no reward, or productive outcome. No “everything happens for a reason” cause not a single reason can be imagined. Just flat out plain senseless wasted time and effort, a ton of it too. You can never get back or make something out of.

How does one get over that, and not let it bother them anymore? Does anybody here have this in life and it haunts you?