I usually get very nervous or keyed up... heart rate increases and senses become sharper and more focused. Crying ...not yet but what you describe is one of my fears... that once I start I won't be able to stop or will do it in other settings. I never thought much about crying, it just never occurred to me that I really don't do it. Recently though the topic has come up and I how realize I have a major hang-up about it.