We want more
Here's a question: how do we know if we wanted to have more classes from a particular teacher?
One might say I know it consciously or have a hunch or I just feel about it - but do we really know? Everyone might have different parameters and it is difficult to group them. However, according to Laurie Santos from Yale University explains in one of his lectures: when we remember something we ignore most of it. According to Daniel Kahneman et. al., study on Peak-End Rule it boils down to two parts to the experience of attending a session with a teacher.
Firstly, the experience has been pleasant or unpleasant. This is going to be a driving parameter.
Secondly, how did it end? was it memorable? This is very well used by marketing agencies or film makers or TV shows by ending on cliffhanger. We end up asking for more!
If one has to go by Daniel Kahneman, its important to focus on - how we want to end.