Why does he act this way?

There's a guy that I am interested in at work. Whenever I see him, I always usually greet him first before he says anything to me. And he is usually polite but doesn't make an effort to keep conversations going when I initiate small talk. He is usually very talkative and extraverted with people and is not a shy person.

When I last saw him I didn't greet him straight away when seeing him as I saw him unexpectedly and looked down out of nervousness but then looked back up at him a couple of times but he didn't look at me at all. He just walked past me and then once he had passed and was out of view he finally said hi to me. Do you think he doesn't like me as it seemed like he would have ignored me completely until he finally passed me and then said something?

Are you new to this job? Perhaps he prefers getting to know people on a deeper level before the awkwardness of small talk goes away for him. I wouldn’t read too much into it anyway, men are strange. Who knows, he might just fancy you and be struggling with talking to you.