What I have heard most commonly is that if your hair is longer wet than dry you have a 3 C curl pattern. Perhaps that is what the instructor is referring to, that you hair hangs in loose curls when wet, whereas someone like me would instantly begin to get shrinkage as soon as my hair leaves the shower/faucet stream of water.

Note: I don't really support the hair typing system because in general because it is way too murky for me to use.

SL
~APL~BSB~BSL~MBL~
WL

You never stop learning...