How about if you just give them the man page for "find" and the /? page for "dir" and see who can get the command correct first?
The brain is a powerful inference engine. A few well-chosen examples can teach 95% of normal people 95% of what they need to know (numbers pulled out of my butt, 2016). Put good examples at the top and marvel at how many more people actually seem like they RTFM.