I Really am a Nice Person

Don't you hate it when you see someone you know, but you're not sure if you should say hi? I always feel like such a jerk in those situations...and very awkward. What is so difficult about making the first move?
Today I saw a girl at the gym with whom I used to work. I never got to say goodbye to her when I left the job, and I regreted that. But, we never exchanged phone numbers, and I was fired- so I didn't exactly have time for info exchanges. I even tried to look her up after leaving the job, but never found a phone number or email address.
So, she walked into the gym and started running on the tread mill right in front of me. I wasn't sure it was her at first, but the more I looked at her (wow...I hope I didn't seem like a crazy lesbian stalker), the more I was convinced it was indeed her. "I'll say hello when she finishes her run", I thought. But I didn't. Then she came over to the elliptical trainer right beside me, and I still didn't say hello! I guess it wasn't 100% up to me to take the initiative, but I feel like an ass for not saying hello. I'm gonna blame it on her not recognizing me. After all, I was never a sweaty mess in work out clothes at work....well, no work out clothes at least.