You've dreamt before, correct? If you have, you'll have had some pretty messed up dreams (eg. being in space playing tennis with a koala. Did that seem real? Don't lie, it did. If it didn't, you would have become lucid. No matter what is happening in a lucid dream, from space koalas to a real life situation it will seem perfectly realistic.

(And pinching yourself will still hurt!!! It is not a reliable reality check. Count your fingers instead)