this thread is depressing to be honest because you will reminisce on the bad decisions that you have done.
I would not consider spending Bitcoin at the current price it was in the past a bad decision, especially as those transactions were what brought adoption to Bitcoin and exposed its use case as a MoE, leading to the price appreciation overtime. If every early adopter had held tight onto their stash and not spent a single Satoshi, chances are it would not be at the position it is now.
Also, if we are looking at future prices, every bitcoin sale is a bad decision. The price is $34k now, in 5 - 10 years, it would likely be way more than that, doesn't mean people who sell now should regret then, especially if you needed the purchased good or service.
It's funny they didn't link to the actual thread on the forum -
Pizza for bitcoins?