I can pass people and smile at them like I do on a daily basis and I don't get looked at like I am a boob. I get looked at like, "today is sunny and we both share this joy which gives me grounds to smile back
I play a game that I learned a while back from my grandmother. She would try and see how many people she could make smile in the amount
of time she had with the stranger. At work, this is easy. Every person that comes in is someone I can say hello to and ask how they are doing. I look at them in the eyes and I smile to them. It isn't creepy if you're being sincere, and frankly, people love it.
Smiles are contagious.