JW beliefs:
The kingdom of God headed by his son Jesus Christ is the only solution to the worlds problems. Jesus gave his life so that we had a shot at eternal life. We must follow in the steps of Christ.
That's it in a nut shell. Not too hard. Why poke fun at that? A bit childish I think.
JW's come all backgrounds, eduction, etc. and some just get nervous when asked simple questions. That does not make them insencere about their beliefs. It does not mean that they don't know anything. If someone asked me 'how is it possible for an airplane to fly', I would freeze, but after a few minutes of collecting my thoughts I could explain it.
Don't judge others, just because you think you have all the answers.