The mall food court worker who corrected my tray habit

Last month at the Eastbrook Mall, I grabbed three different sauces and stacked my tray with two drinks like I always do. A guy wiping tables stopped me and said, "You're gonna drop that soda before you find a seat, watch." Sure enough, I turned toward the ramen spot and the cup tipped right over. He handed me a napkin pile and showed me how to put the drinks in the cup holder first, then slide the tray's edge under the food. I've eaten at food courts for 15 years and never thought about the order of loading things. Now I line up everything before I touch the tray, no rush. Has anyone else had a random stranger point out a habit you did wrong for ages, where you just nodded and felt silly?