If you really like something and make it your business to study up on its history and characteristics, you could be called an aficionado of that subject.
This sort of funny-looking word might seem like it needs a second “f,” but it really doesn’t, and you should hold out on the temptation to add another one. (The single “f” spelling is a result of the word’s Spanish heritage.) The word aficionado implies serious study and fervent interest — it’s often applied to lovers of wine, known as wine aficionados — but you can think of it as just a fancy way to say fan. You could call yourself a football aficionado, for example, if you think that sounds more impressive than just saying you’re a football fan. (Though that might get you beat up in certain bars.)