If nobody cares, why should I?

I came across a quote on tumblr which I thought a lot about:
"If nobody cares, why should I?"

If nobody cares, you will see them on the streets one day and avoid eye contact with them, then spend that whole night looking through their Facebook account. If nobody cares, they will think of you when your song comes on, and they will have that song on repeat for the whole week. If nobody cares, you will constantly find yourself trying to justify yourself for doing the right thing by disregarding, even though deep down you feel like you didn't. If nobody cares, they will think of how you left and question themselves if they should have held you back (they should have).

But that's that.

Because if nobody cares, the more you will start to care, and there will always be two unhappy strangers, wondering about the 'what if's for the rest of their lives.