Am I being dumb??

So I used to have a major crush on this nerdy guy Alex and we would text regularly and it was great but then he got a gf so I got over him. After they broke up he started messaging me again but I wasn't as interested so we just kinda stopped talking for like a year. I was in a kinda bad place so I reached out to him to start talking again and he told me that that wouldn't be a great idea because he used to be into me and he had a girlfriend again. he said we could be friends but I told him nah because I'd probably get feelings. that was the end of that, and I unfriended him on everything. now he has suddenly become active on my social media and has asked to follow me again on stuff. I've also heard from our mutual friends that he's been mentioning me a lot lately. maybe I'm reading into this too much, but I feel like he's going to try something soon. I'm living in anticipation. I'm just generally confused about the whole situation and need advice. help?