My first actual clear memory of liking them is from when I was about 5 and a half.
For some reason, some last-minute changes travel arrangements resulted in my mom and I having an unplanned overnight stay at my grandma's house during the holiday season that year, and since we had no intention of actually spending the night--I obviously didn't have any other clothes/stuff to sleep in. And I do distinctly remember that the clothes I had on at the time were kind of dingy/dirty, because it had been snowing hardcore that week.
I don't really remember how they landed on this specific combination, but for whatever reason my grandma suggested that for the rest of that evening/bedtime I wear an old plastic-backed 90's diaper that had been leftover from some other grandchild that she found in a closet. I can still remember the specific closet/drawer they were in to this day!
I ended up wearing it, and a huge old Dallas Cowboys tshirt that had belonged to my uncle for the entire night while our other clothes were being washed, and actually have bits of that trip caught on really shaky, grainy camera that my mom filmed while we were there (since it was Christmas season).
I was a really shy, private kid. And I remember even back then being super freaked out and anxious about getting that diaper put on (part of why the huge t-shirt became a thing not long afterwords) but I distinctly remember being blow away at how comfortable it felt wearing it. I *think* it was a Huggies, but I don't 100% remember, other than they were for certain plastic backed, and fit me really well at the time.