Until age 17 I thought of "a couple" as being an imprecise amount more than "one" but less than "a few". So around 2-3. Though when referring to people I always thought of it as =2.

It wasn't until 17 that someone (my girlfriend at the time) pointed out that by definition it should always be 2.

I'm not sure why I thought there was some fuzz in there. I also don't know why nobody had corrected me until then. I can only speculate that I and the people around me usually said "two" when we wanted two of something. The rest of the time I suppose I had a 50/50 shot at the right answer.