He lets a person be flexible to some extent, but then all of a sudden he just breaks. He doesn't melt down slowly; he quickly starts getting very upset, often over "tiny" problems.
Glassman usually thinks things aren't "fair".
Some ways that Superflex suggests taking on Glassman:
Identify the size of the problem and what would be an expected reaction to match the size of the problem.
Self-talk: "I'm starting to get mad. I need to move away and take a break."
When getting frustrated, tighten all of the muscles in my body and then relax them.