Why are short people sad?
Don't judge though, it's crap but...
Because they couldn't reach happiness.
Short People's Sadness
Explanation
Explain Bear
Listen up, buttercup. The joke is that short people are sad because they can't reach happiness, as in, they are not tall enough to reach it physically. It's a play on words, see? You probably think a 'play on words' is when actors are messing around on stage.