I have several that were all formative in a certain way.
My mother loved food and having grown up in California, at things like avocados and artichokes, things that no one in the tiny Midwestern town I grew up in had ever heard of. My father was typical of many in that tiny town: beef (well done), chicken (fried), lunch meat sandwiches, potatoes (any way), and veggies. At least he did prefer fresh or frozen to canned, though he still liked them cooked limply.
So, when possible, my mother would escape with me and the two of us would go places my father wouldn't dream of going. This led to many trips to Galvez' in Frankfort for Mexican, Cliff and Tommy's in Monee for Chinese, etc. This in itself is still memorable - the monthly experience of being with my mom, just the two of us, driving to one of "our" places and eating delicious food together.
The first single memorable experience from this collection of experiences was at Keith's, a restaurant in Homewood. I was probably 4 or 5 years old and wanted to try lobster. My mother agreed and I was smitten. I can't remember much about the restaurant, just that it was dark and full of people enjoying themselves, with a waitress who actually appeared to like small children who appeared to enjoy dining out.
The second was similar to one upthread. My mom believed that I should know how to cook and entertain. I always participated in cooking and baking our meals for the three of us, but at eight, she decided that I should be able to cook a meal for a group. I don't remember know who was invited or what was on the menu, but I was in charge of creating a menu and cooking a meal for six. I am assuming it was the three of us and my grandparents and my uncle, but I don't know. I do remember, though, that feeling of accomplishment; that if I could do this, I could do anything!
Thanks mom.