What is wrong with me? Do I have a disorder? If I do, what?

I am 16 years old. I've always been forgetful, but i used to think I was just a little bit more forgetful than most people, but it was nothing to serious. Now i'm reconsidering that. I've been slowly getting worse, I used to be really good with names, but the last two years, that has changed. At first, like I said, I thought it was nothing, until last night. I have a best friend who I've known for quite sometime. Yesterday he told me that we've made out before, before a year ago. That would've been something I would remember you know? But when he told me, I was mind blown. I seriously had no idea, and I still don't even when he told me all about it! If i forgot this, who knows what else i forgot! So someone please tell me is there's something wrong with me, or if i'm just overthinking this?