I like MFK Fisher's story of the "Hindu Eggs" she cooked for her sister as a young girl, adding curry powder so liberally that her lips blistered. But she was too proud to admit defeat and ate them all.
I used to spend my free periods at school in the library, reading cookbooks. I was 11 years old. Having pored over the creme caramel recipe for weeks, I finally signed it out of the library, went home and made the damn things in a bain marie (I went to a French school so this didn't sound too alien to me!). They turned out perfect and I was hooked for life (in culinary school now).
What was your first culinary milestone, successful or otherwise?