I am with a man 10 years younger than me, and I reckon the age difference matters more to me than it ever would to him. In an annoyingly stereotypical and paranoid way, I worry that I will start to look 'old' and he'll end up doing one with someone his own age. He generally tells me to just stop being a silly cow!
On the plus side (of which there are many ), I find him refreshingly free of all the utter ******, baggage and pretensions that older men (in MY experience, I hasten to add!) bring with them.
He also doesn't pass out from exhaustion after peeling a feckin satsuma....or summat;)