1) When you're checking in, instead of verifying your name, address, and insurance information, the receptionist says, "Nothing's changed since yesterday, right?"
2) You recognize some of the people in the promotional posters hanging in the waiting room. "Look-- it's Dr. M! And isn't that the nurse that...?"
3) You know to request the paper tape for the I.V. Regular tape is for suckers!
4) When the person you're waiting for emerges from what was supposed to be a one-hour procedure 2.5 hours late, you say, "Wow, that's it? You're done already?"
5) You can't remember where in the parking garage you parked the car. Level 5, on the uphill side? No, that was last time. Dammit.