I will explain it this way,,,
I live in an area where we go Flounder gigging all the time,, When I first started ,, I was sticking every dark spot in the water,,, thinking that ,,,maybe that was a flounder,,, never was,,, just a dark patch of sand

one night after my latest evening of sticking several hundred patches of dark sand,,, I walked up to the beach where there was this ole timer with a nice stringer of flounder he had gotten that evening,,, I was telling him my woes of not being able to tell the difference between a dark patch of sand from a flounder,,, he just laughed at me

and said,,, don't worry about it son,,, the first time you see a flounder,,, you will never stick a dark patch of sand again
Once you see a Eclectus mushroom,,, you will never again confuse it with a Jawbreaker