My time was also young. Mom bought my underwear and they were always tighty-whitey Hanes briefs. I was at my Grandparents house with a cousin about three years older. We were alone in a bedroom.
He was giving me a hard time about everything. He grabbed the waist band of my briefs and pulled them up into a huge wedgie. He laughed about it, but it sure hurt. I couldn't figure out how to get the wedgie tucked back into my jeans. He laughed more at my feeble struggles and said, "You know, it'll be so much easier if you drop the jeans and then adjust." I'd never dropped trousers in front of an audience before but he just laughed at me.
Finally, he said, "Fine. I'll drop my jeans, too." He had on fire-engine red briefs with a black waist band. I desperately wanted to pair just like his. Since then, I've always wondered at the surprises hidden beneath pants.