So cool to find that tucked away in a gift shop. That is what I love about collecting coins. They can send one down that research rabbit hole and learn so much from it. If you are a history lover, then it is something that you can't resist sometimes. I agree, there is so much the U.S. could learn from the failings and successes of the Roman and other empires. We just can't seem to do it though.
I collected coins as a child and loved the hobby. Whenever I'd get a few extra dollars I'd run off to the coin shop. What I learned about this particular coin was a little depressing, ironic because I tried to chose the least depressing design! Lol. I guess this Roman emperor, Gallenius, was even kidnapped by a Syrian king and held hostage.
I first started collecting in the 7th or 8th grade of school. I have been off and on ever since, but only as a hobbyist, never too seriously until recently. It sounds like you learned a great deal and it was rather interesting even if it was rather depressing. Sometimes history can be depressing and ugly. We shouldn't shy away from that or try to hide it away though as it is a part of us and how we learn.
I started around the same age and stopped right before I went to college. I transferred my addiction from coins to vintage watches in my mid-twenties. Lol. I love collecting, and have met some wonderful people along the way. In a way it's almost like time traveling.