sounds like you have a gay stalker my friend. FYL OP LOL

That doesn't mean you haven't mentioned them at work before. I bet he likes you and remembered what you said.

May be u said it somewhere in the office or to someone... He took an extra interest and brought them for ur bday to make it special for u... If he hasn't behaved creepily at all in past few days, I think u found urself a great friend... Just chill and be happy

Hasn't anyone thought that she may have mentioned it at work as well and forgot?

Stalker, run away!!!!

Calm, OP. He might like you, and you mentioned it at work, so he bought them BEING NICE.

At least someone cares about you :)

I'm failing to see the negatives here. You got flowers on your birthday. You have also continuously made a positive impression on a coworker, which is not a bad thing, romantic or not. I also don't see how this guy is a creep. Just because OP hasn't made the effort to get to know this guy doesn't make him a random person; they WORK together. I used to work in an office of about 200 people. I didn't know everyone, but I could tell you at least one fact about each of them. Whether you intend to or not, you observe your coworkers. And if someone makes a positive impression on you, you are going to observe more. Plus coworkers talk. You could have mentioned sunflowers to a coworker who told your admirer. Or he could have overheard. Your coworkers will know things about you whether or not you make an effort to befriend them. That's office culture.

Chances are you mentioned it at work before, or he is friends with someone from your family, but nobody told you about it. The world is smaller than it actually is at times, so if you are really curious, you can ask him how he knew about it.

Well then. That's creepy.