Is it unwise to date an older guy?

There's a twenty-year age difference between me and my coworker...since my first day working at the store, he's liked me. I didn't know my true feelings towards him. Three days ago I decided to test things out and start dating him. So far I'm enjoying myself, and so is he. Is dating someone with this age difference a bad idea?

Working with him isn't a problem. My manager is dating one of my coworkers, my best friends who also work with me are dating...so why can't I date a coworker as well? The main issue is the age...is it that big of a deal?