My favorite TSA interaction occurred in LAX at terminal 3 shortly after the Delta move.

*while going through KCM scanning my badge for a 5:15 AM show time*

TSA Agent *while viewing my ID*: "You seem a little young to be an airline captain."
Me *due to the early hour, my filter hasn't yet finished its BIT*: "Well, that's because I'm not a real captain."
TSA Agent: "What do you mean?"
Me *realizing that answer might not have been the best thing to say to the person responsible for verifying my airline credentials*: "Well, I don't get paid like one!"

Fortunately I got out of that one with a chuckle and fortunately didn't have to explain the whole regional vs. legacy pay scales for pilots to that TSA Agent at 5 AM, but I know it easily could have happened. Now I've learned to say "Thanks. I just got my Botox shots yesterday." It is LAX after all!