I get it.
Not every day is going to be a rainbow wrapped butterfly with a cherry on top confection. I know that, and so do you.
But my motto is: if you can’t be the sun, be the moon.
That is, if you can’t radiate goodness and happiness like the sun, then the least you can do is reflect it. Be the moon, reflecting the light from the sun’s rays. Be the moon, and reflect what little good there is in the world.
So if someone is nice to you on a day where you don’t feel like the sun is shining very brightly, then pass it on. Reflect that goodness. And shine a little brighter for it. Even if that’s all you can do — hang in the sky and reflect. Even if all you can do is be the moon.