Re: If you're in the bizz long enough, you'll crash a production machine.
I once took out a Beowulf cluster by changing my windows password. I mean, it was a /terrible/ setup, 80-odd PCs running windows XP, with regular user accounts - in this case muggins, hence the whole thing going south when my password changed - but it worked well enough most of the time.
And I'm not even a sysadmin! It's inevitable that if you have the power and the admin rights to break almost anything, you'll break *something* eventually.