Well, @Fraca, I am NOT one of those who will be derogatory towards you, although I am also not one who is embarrassed to laugh alone in public. In fact, I'm one of those who you NEVER want to sit beside during solemn events. Nor was my father.
Prime Example:
My father's mother's funeral. She lived in a town that originally had two funeral homes. One family had an only daughter, one family had an only son. They grew up together, fell in love, married, and in due time, combined the funeral homes, hyphenating the family names for the "new" business.
When Gran died, they, of course, handled everything. Dad and I were doing fine, holding it together, until the actual service. Dad was looking at the printed program, and suddenly his shoulders started shaking, I looked at him with alarm, thinking he was crying. Nope. He pointed to the bottom of the program, to the name of the company, and it hit me, too. We KNEW THIS, but somehow, in that moment, it took on highly comedic aspects...my beloved grandmother was sent to her eternal rest by the fine offices of Rideout-Underwood Funeral Home. Thankfully, my mother was able to pass this off as grief, to all but a few.
In retrospect, and after almost 6 decades, I realize it was stress and tension being released, but at the time it was just FUNNY to us.
So, yeah, I get laughing where you think you ought not to laugh.