Is it normal if gintama is the saddest anime in my opinion?

I've watched lots of sad and depressed anime. Clannad, Clannad ~ After story, Angel Beats!, Hotarubi no mori e, Air, Kanon... Those famous tragedy anime didn't made me cry even a single time !! The closest to my heart was Ano Hana (very depressing) but I still couldn't cry.
And I never expected myself to cry cause of a comedy anime - Gintama. Everyone said this anime was funny, but to me, it's the only anime which really got my eyes wet. I don't even know why. Does that made me inhuman?