To add to Chris' comments, remember that there are websites that archive pages. Archive.org is one of them. If you want to see a site's contents from three years ago, they just might have it. Google also caches pages, but for a limited period. Deleting your entire website would not make it inaccesible to someone who is curious and resourceful. (I notice that SOG seems to have a way to override this. They have cached pages on archive.org, but the site blocks them. Cynthia has a good webmaster).
Here's what Yahoo looked like ten years ago...
http://web.archive.org/web/199610172...ww2.yahoo.com/
Sometimes I regret things I've posted on the web, and I especially regret that I can't delete it.