I have all my pm from 2001. The most interesting ones are from my years as a moderator.If there were a button to immediately erase every single one of those posts, I'd press it in a heartbeat.
Since XenForo, I've probably deleted 400+ of my own posts. In most threads these days I'll make a post and reconsider within seconds and then delete it. Sometimes I get burned and someone's already quoted it in a reply.
ETA: By purge all evidence, I meant profile posts and PMs. I don't have a single PM from before 2019. And I'll probably clear that out again soon. It wigs me out that there are people here who probably still have PMs from me pre-2016. Possibly even pre-2010.
While a super moderator, I did go through and clean up a lot of my very early posts and where they were quoted. Hidden nuggets no one needs to know about.