After having bought a personality test a few years ago for more accurate statistical measurement I learned that I am practically at the bottom percentile for enthusiasm, and just recently I realized it to be something that affects me significantly in the social aspect.
I just never get excited about stuff. If anything, what results is anticipatory anxiety more than excitement. And being enthusiastic about anything is practically impossible. It's not like I'm not happy when doing activities that I love, but rather I don't have this capacity to show it in an outward manner.
And the thing about enthusiasm is that I can't fake it either. It's impossible to fake for me. If I try to fake it, it sounds entirely sarcastic. And it honestly is. Even if it is something for me to be enthusiastic about I just cannot seem to do it. Since I can't even be outwardly pumped about something, I ended up with this weird perception that enthusiasm is synonymous with being fake. It's less of a truth and more because I am actively being dishonest if I try to look enthusiastic about something. Some people can be very enthusiastic, but I often shy away from those people because it's a bit too much for me, personally.
As an example, it has become an inside joke in our friend group that no matter what I eat, I always say "it's OK", regardless of whether it's bad or really good. I don't know what to tell them, but I am being honest when I say that. It's not like my tastebuds are shot. I can still taste whether something is good or bad, but I'm not going to go up and arms and pull out a megaphone telling everyone how bad or good it was. I suppose it's not in my nature to really do that. And it's probably why I'm horrifically bad at writing reviews, which is made evident by practically everything in the showcase section.
I think enthusiasm is more of an outward expression of one's inner passion. You can be passionate and not be enthusiastic. That's basically me. I can do an activity for hours and love every second of it, but if you wanted to talk to me about said activity you'd be hardpressed to think that I love doing what I do. And it's more because my tongue functions like a delapidated fruit roll-up than an actual tongue. That, and I'm just not the type of person who even remotely looks like someone that's enthusiastic. It's too out of character for me. If I tried to even be remotely enthusiastic people look at me as if I'm in an elementary school acting class. It's utterly horrific.
But hey, as a result of low enthusiasm I don't typically fall into hype trains. At least I have that going for me.