Negative T-shirts

I don't understand why some people wear negative t-shirts. Yesterday, I saw a
woman wearing a shirt that read "If you can't buy happiness steal it." I wondered...
How do you steal happiness? Do you steal items to be happy, or do you make
someone else unhappy as a way of stealing their happiness, therefore somehow
turning it into joy?

Wearing a negative t-shirt is like broadcasting to the world that you're a negative
person. I wonder why someone would wear a shirt that clearly tells everyone that
they're unhappy? I try to stay away from negative people, especially when it's
written all over his or her shirt.