Good Etiquette

My Wife, Daughter and I just got back from having lunch with friends at a local restaurant and I decided to write about good children restaurant etiquette.
We decided to order our daughter a grilled cheese sandwich for the first time (she's one) and let her feed herself. As you can imagine, it was a little messy. Instead of saying "Dad, I'm full and will not be finishing my plate" (again, she's one), she decided to start tossing her food onto the floor under our table. Since we are not mind-readers, we assumed she was just being a little fussy trying a new food and all, and continued to encourage her to finish her plate. More grilled cheese pieces on the floor.
After we finished our meal and paid the bill, a good amount of grilled cheese had piled up on the floor. As my friends and family headed outside the restaurant, I decided to stay behind and pickup the grilled cheese pieces that had fallen/tossed to the floor. While picking them up a pair of hands came into view and moved the high chair out of the way so I could easier finish my task. As I turned my head into the direction of the waiter, I noticed 3 other waiters/waitresses staring at me. I decided one of two things: they had never seen a customer cleaning up after themselves, or they thought less work for "me". In either case, it was the right thing to do.
I remember once I was seated next to a table of three mothers, five children and a pile of food, napkins, silverware and glass under their table. As they were all leaving the restaurant, I decided at that point I would never be one of those parents. Of course we all get busy and sometimes need to skip certain steps during the day, but a general rule of good common courtesy should be followed. I did decide to give the mothers the benefit of the doubt. I'm sure they were busy like the rest of us, but I quickly retracted that thought as I was leaving the restaurant and saw that they were engaged in conversation 20 minutes later.
Of course a one year old probably wouldn't understand the nuances of etiquette and common courtesy but that's the point. When do you teach these golden rules? 15 months? 22 months? We don't know. Again, we're not mind-readers. So I say teach your child about good manners as soon as possible. It's easier to err on the side of caution.

I appreciate your interest.

Thank you,

The Dad