Why do contributors delete their own posts?


A significant contributor who shall remain unidentified deletes posts shortly afterwards. It’s not done with the intent of correction, but for the purpose of limited viewing. I wonder what rationale warrants this behavior. It certainly not for the benefit of providing context for later viewers who might want to learn from the thread. 
128x128celander
Don't be jealous, it took years for me to build myself up to 80%.

This may have already been mentioned, but I think that if a poster deletes his/her own post, it says something like "post removed and the date".  But if the mods delete a post there is no evidence it was ever there in the first place..
jetter, the appearance of a deleted post is not dictated by how it gets deleted.