sadness is tiring. 
being sad for a long time and trying to get out really exhausts someone. in a way, being sad is like running on one of those nightmares where you can't move no matter how hard you try to.

you try to run, but the ground beneath you is still the same. you try to be happy, but something or someone keeps pushing you down. you try, but what's the point?
and then you're able to run for a minute or two, and it feels glorious. you're able to be happy for a day or two and you forget all the rest.
suddendly, you don't care that you weren't able to run. you don't care that you were miserable for days, weeks, months, because that something or someone made you happy for a change.
but then you trip and you're stuck to the ground and you can't move again. that something or someone goes back to what they were and again, you're stuck with sadness.

so you ask yourself: why do i try, if everytime i do, i go back to where i began?

you're tired.
of running. of staying. of everything.
and you just stop.

people say you're lazy, that you didn't try hard enough.
but you just grew tired.
everyone has their limits.