Agreed. In questioning clearances, instructions etc., I would also strongly advise caution against "confirmation bias" as well.
In other words, instead of asking "Confirm ABC123 cleared FL150?", ask "Say again our cleared flight level? ABC123".
Especially when in a viatal stage of flight, or when your action will be difficult to reverse (e.g. entering the runway), if either pilot (or FE) is in any doubt, always check, and check again with ATC until both (or all) of you are in no doubt as to what it is they want or have cleared you to do.