What does it mean when a guy doesn't reply to your texts?

I'm pretty sure he likes me. Like 98% sure. He was the first one to text me after he got my number from where ever. I like him too, but recently whenever I text him first, it seems like he doesn't want to talk to me and seldom replies. And just recently he hasn't been replying at all. What does this mean?? Is it just a guy thing err what?? HONEST OPINIONS PLEASE(: