You know you're an old school D&Der when your favorite sub-forum is near the bottom of the page.
You know you're an old school D&Der when you describe your character's action to the DM, the DM looks at you with a blank expression, tells you "Roll against skill/feat/power X" and you look back at the DM with a blank expression.
You know you're an old school D&Der when your character dies and you have another ready, from scratch, in under 5 minutes.
You know you're an old school D&Der when every single thing you need to play, including ALL
rulebooks, dice, player sheets, notepads and pencils, fit into one standard-sized cigar box.
You know you're an old school D&Der when you run your original D&D at CoastCon, and people actually stop and oogle over your books. Your entire '74 boxed edition that cost you about $10 bitd now go on e-bay for hundreds.
You know you're an old school D&Der when you think Lou Zocchi has the coolest booth at a convention.
You know you're an old school D&Der when your rulebooks are about as old as some of your players parents.
You know you're an old school D&Der when you have trouble finding players.