Ooof. I had to send a very significant amount of Bitcoin to a different wallet the other day and oooh man. I still triple check an address even if I copy and paste it.
Discussion
Ironically enough, I know that it's because the Bitcoin network works too well that I'm paranoid to send it somewhere that's not under my control. A mistyped key or a non-capital letter somewhere in the address will completely screw me over.