Tipping - is it mandatory?

I have always left tips at restaurants. Sometimes I leave 10%, other times I leave 20%; I've even left 30% before. Up until last night, I can honestly say that I had never NOT left a tip.

So what's the deal? Why was last night different? You be the judge!

I took the Little Man to a restaurant at the mall, a family restaurant (it's a cute little 50's diner) that we've dined at many times in the past. We've always had exceptional service and good, if not great, food (may I recommend the Grilled Shrimp Club Sandwich, yummm!!!). Anyway - the Little Man is a little on the independant side and loves to order his own food. This usually has the wait staff cracking up and in my book - you score points with the kid, you score points on the tip. $$$ The lady last night seemed less than smitten with my adorable young man (who can resist his charm and excedingly good manners?) "I would please like a cheese sandwich, and fries, and lemonade, and white dip." "Thank you!" Come on now, give it up for the five year old who says please and thank you without reminders! Granted, she might not have a clue what 'white dip' is but most people can figure out that the boy wants some ranch with that.

Okay, obviously she's not a big fan of the shorter, cuter humans - I can't hold that against her. I can get mildly annoyed when my iced tea is gone before my meal arrives and she says "I guess you're gonna want another one of those, right?" Yep, that got on my nerves a bit but I can look past that too.

I can even turn the other cheek when she comes to check on us and leaves my empty plate sitting in front of me when she walks away. Annoying, but not 'tip-loss' worthy.

Here's where she looses the tip.

I paid with my debit card. Stuck it in the goofy black foldery thing and she took it to ring up my bill. Then I watched her take it to the WRONG TABLE! She's caught up in her spiel about top copies and bottom copies and have a great night, yada, yada, yada. The man at the table is trying desperately to get her attention and she just won't have it. Finally he says (rather short with her) "Excuse me!" She looked stunned for a moment that he dared to interrupt her. "This isn't mine." Then she says something like "oops" and walks off, over to my table. She hands me the goofy black foldery thing and says (laughing) "I just gave your card to the wrong table." And then she walks off.

She. Just. Lost. Her. Tip. Luckily this guy was paying attention. He could have easily signed the receipt, put my card in his wallet, and walked away. He could have been some identity thief and thought "Hot Damn! It's my lucky day!". Thankfully he was an upstanding citizen and did the right thing, and luckily I saw the whole thing happen. It could have been really awful, I don't do awful very well.

So...are tips mandatory, or are they a direct reflection on service received? I don't judge a tip by the food - that's the cook, not the waiter/waitress, but you most definitely have control over what table you take my card to.