Thses are confusing at times, and new ones crop up from time to time.
I make up my own sometimes, and whether they are right or wrong, they work for me! Don't worry about being "dumb" on this forum. Sometimes I have a brain freeze and what I used to know, is no longer filed in the right place in my brain, and I can't pull it up to use it right now.
So ask away with out reservations.
IMHO - in my humble opinion