5. You find yourself shamefully hiding accidentally-bought second (and third, see note for #2) copies of a game you haven't played yet.
4. You own Metroid:Other M, Aliens:Colonial Marines, AND Amy.
3. You excitedly rushed to add a game to your shopping cart during a Steam sale, only to realize you've owned that game for six months.
2. You buy games before 6 a.m. (seek help)
1. You can't pirate games. I don't mean you won't, I mean you can't. At best they're cracked backups of your library.