The old timers don't have to understand why you collect what you do. The key is that you enjoy what you collect. The experience of each generation is different which will lead to the different collecting tastes. I think my dad grew up on westerns so his interest is in the single action revolvers and lever action rifles. I grew up playing war with a hodge podge of military surplus items; World War I and II helmets, belted ammo, two law rocket launchers, and military jackets and such. We would build forts called Naverone and run around the woods all day. I think that is where my military surplus interest came from. The end goal for all of this is enjoyment.