Not remembering is one thing, but if they find out during the vetting process, and then they ask you about it, your answers had better be forthright.

> There is nothing morally wrong in felonies like this, just don't get caught.

Highly debatable. If you believe in a categorical imperative that to intentionally deceive another person is wrong, then lying by omission is still an immoral act. A Christian might also interpret the words of Jesus “Render to Caesar what is Caesar’s” as an imperative to comply fully with the law of the land.