I don't think it is about dumbing down as much as it is about not talking over someone's head. I've met people, and I'm sure you have also, who "ride their education on their shoulders." They talk with all these big words and about all these big topics because they want you to see how educated they are. No one likes being talked down to. I went to law school, but my husband never went to college. He went into the Air Force after high school. Sometimes when we are talking, I'll use a "big" word and he'll laugh saying, "is that the big "a" word for today." Then he'll ask me what the word means and we go on from there.
As far as giving your real age, age is just a number. I didn't start dating my husband until I was 42 and we got married just before I turned 44. He always knew how old I was. You don't want a relationship with someone who can't accept who you are, education and age wise.