This is incredibly true for me. I blocked time sink websites (like HN ironically) in /etc/hosts for about a day, and then I constantly went back and reverted my changes. Then, I wrote a daemon that constantly checks the host file and puts the blocks back if I changed it. I tried making the installation and operation as obscure as possible and try to forget the metaphoric key. However, I eventually ended up spending a bunch of time to rediscover what I did, so I ended up disabling this script as well...