What’s a mistake you made by being impulsive?

I’m looking for cautionary tales to curb upgraditis.

After living with the same speakers and integrated for 20 years, I’ve now replaced everything in the last year. I even have a list of next steps that may or may not be necessary. Like I probably should finish mounting all my acoustic panels before getting a subwoofer. And do I really need a better pre if I only use one source and might eventually upgrade to a DAC with volume control? Did I mention I’m waiting for new speakers to ship? But SET amps sure are interesting and now I want one of those, too.

So when did you make a purchase and then immediately regret it because you decided to go a different direction?