I had a conversation with a friend the other day who basically stated they always had a hot dog when they were at a baseball game. From my experience, that's somewhat standard practice with many.
Another thing is my personal bit of whenever I fly on a plane, I always have ginger ale, a habit which I found out was more common than I thought. I didn't even know of the calming digestive effects it has for some, but for me it just became a habit almost out of nowhere.
What I was wondering if any of you had any more unique examples of this notion. For example, if I have a beef hamburger, it's almost always a gourmet versus a fast-food variety as I don't eat burgers much at all these days. However, when I attend park picnics where they're grilling standard frozen burger patties over BBQ pits and using standard buns, I'll always opt for a burger as long as they have things like lettuce, pickles, onions and mustard to top it off.
Another one for me is a family tradition of sorts that developed over the years - whenever it's New Year's Day, the family would steam up and eat palitaw, a Filipino rice cake dessert. There's nothing really that I can find that would link this dessert to New Year's Day, but for the most part that's the only day during the year when we steam up a batch..