Animals don't think.
I taught my cat to ring a bell for food. I first hung the bell next to the bowl. Eventually the cat rang the bell just to check it out. When he rang the bell I would give him a small treat. Then I took his paw and rang the bell and gave him another treat. Then he got on the program and we repeated it 7x. 7x is a magic number for my training.
The big problem with behavior training is humans. Humans think. They are inconsistent.