Being excited about your hobby or pets is something that is usually infectious to others. As Jen mentioned, it makes an enormous difference when you take the pressure away. Not everyone is going to come around, and simply respecting their boundries whether its "I don't want to hold it" or "I don't want to hear about the reptiles" puts them in control. Nobody likes being forced to do anything, so when it is simply an option or they see the positive side of keeping reptiles and the interesting facts about them it leaves room for their personal curiosity to come around.
Many of my co workers have written me off as that crazy snake lady (and now roach lady) but it's affectionate, and most of them know that if they hear/see/read anything reptile related I can bring up a great conversation. It's been enough to convince one of them to wait on my first clutch in order to get a baby ball eventuallyLong wait, but it makes me smile