At age 3, my earliest retained memory was of my Mom giving me a peanut. A few minutes later, my family would find out that I was deathly allergic to peanuts, and I was whisked to the hospital where shots were in store. It was traumatic for me because I wasn't really sure what was going on, and the sight of so many shots in my body was a little weird. As far as I can remember, I allowed the doctors to do anything they needed to do though, so the experience was painless (not really). At my current age, 19, I have thus discovered many more allergies, none as severe, but all slightly irritating. I'm not afraid of needles because I know that they are the quickest way to recovery, and I like to think that I am as agreeable as I was when I was a young'un.
Well, I'm glad you were okay! My earliest memory also involved something borderline traumatic (maybe that's typical of first memories?). Anyway, in short, glad nothing worse happened. XD