[OnyxFlame]

This is where common sense comes in: If you don't think you can play it halfway decent, don't try it.

My current char is at least as smart as I am. She generally plans things well and tries to stay a step ahead of whoever might threaten her. Yet when faced with tough math problems, she asks someone else to solve them. (She also has a crappy memory, which I really wish she didn't, but my memory isn't that hot either so there's not much I can do other than logging every single thing that happens, which I don't feel like doing.)

Anyway, back on the main topic. If you find yourself in a situation where your char should know something but you don't, just keep your mouth shut. You could pretty easily make your rocket scientist type be shy or have bad self-esteem, and avoid having to spew technical details as much as if he was deliberate. "Oh, you don't REALLY want to know what I think, do you?" Or there's the haughty approach: "You wouldn't understand me if I told you."