Confused on what this can possibly mean?

So there's a really hot guy that I have a crush on. I added him on Facebook and maybe few months later I ran into him when I was walking my dog, we walked our dogs together for a bit and after that month later maybe he message me just saying what's up had a regular convo and then recently he messaged again saying what's up and stuff! We don't go to the same school and he's knows a lot of popular girls but he messages me out of everyone?! What does this mean? Does he like me!? My friend thinks he likes me but I don't know! Honest answers plz thanks!