Is it normal my neighbour texts me but dont say hello in real life

I am a woman and I have a male neighbour same age as me. He texted me a few years ago "Hi" and when I asked him who are you he told me that he lives in my building and we met outside. I asked him what he means by "met outside", and he told me I had walked past him... :/
We texted a little and then I did not text him again but he has over the years kept going "hi", "whats up" at random times even though I dont reply. He also asked me once if i'm single lol.
I quite frequently run into him in the stairs or outside and the funny thing is he doesn't say a word to me. I'm an introvert and I dont say hi to anyone, I have no interest, but he's texted me multiple times... Funniest thing is he said that when we meet outside again he's going to tell me that its him yet he never has xD I dont think hes a creep though. So odd to text me and act like nothing in person. Does he think I dont know what he looks like or something?!

This is the second weird encounter with a neighbour i've had in this building by the way. Once I matched with a neighbour (who moved years ago now) on Tinder as a joke. He started texting me and trying to make me go for a walk with him around the building lmaoo and I once ran into him in the stairs while taking out the trash....So he was standing in the elevator like "hi! whats up with you?" while I was on my way out with trashbags in my hands. And then he texted me in the app like "it was nice to meet you :)" lmaooo. Years later, when he had moved, I complained to his mom with a note (who still lives here) about her dog barking nonstop all day and threatened her that i'm calling animal services. Since then she walks her dog everyday. I have a feeling its his dog that for some reason he left because in the past I saw him walking it.