Classmate "bullying"

[DizzyPixie]

I have a classmate (I don't know if that's the term, we're in university) who is acting weird. He's 38, he lives with his parents and this is the 3rd or 4th university program he attends. He hopelessly tries to make friends by "spamming" the facebook group with "good morning, friends" and "goodnight, friends" and "why don't you all come to my village some day!" and acting like everybody is his close friend when actually he has no friends, at least in the class. He's acting like a child in general, he raises the hand in classroom like he's the "teacher's pet" and shows off his knowledge. If somebody says he knows how to do something he'll immediately say he knows it too. I know he sounds kind of arrogant but actually he comes off more as desperate, like he doesn't know how to approach people. He says lots of silly things like "I love taking exams!", his speech is slurred to the point you need to try hard to understand what he's talking about. He looks like he has some kind of mental issue, at first I thought he had an intellectual disability but now I don't think so because he knows a lot, he just seems very immature. And he's clumsy, like, in the lab (we study archaeology) he can't handle small or delicate things without breaking or dropping them. Even when he takes pictures he covers half the lens with his fingers, and then uses the photos in his essays.

Now, to be honest, I don't like him. He annoys me when he starts to brag about how many degrees he has or about how we should use more "sophisticated words". On the other hand, I know he has issues and I know he wants to make friends. He's like a 7 year old with a good memory. But others make fun of him all the time, and I know he understands it, even if he still tries (too hard) to be friends with them. I want to help him but I don't want to be his friend. I don't mean to be mean, the fact that I don't like the way he's being treated doesn't mean I particularly like him as a person. Plus, he hits on all the girls, myself included. I don't want to get too close. But I'm starting to feel bad about him. They make fun of him right in his face. I've never done that. Once he got on my nerves by bragging and I told him to stop it, directly, and I was expecting a fight, but he just looked scared and said "...I'm not bragging..." and since then he's extra friendly to me, like he wants me to "like him again".

Do you have any advice on how I could do something about it? I told my thoughts to another guy and he replied "well, it's rational, what they're doing to him. He's ridiculous".