"when you're falling in a forest and there's nobody around do you ever really crash or even make a sound? "

If you are referring to the philosophical thought that has been pondered upon for centuries, then it actually refers to the question - Can something exist without actually being perceived? If you fall or make a sound in a forest where nobody can hear you or see you, did it actually happen? There is no definitive answer to this, as it is open for discussion.
However, if you are referring to lyrics, then it is a song from Dear Evan Hansen, called Waving through a Window. 

Ifeel like this means that we shouldn't just live for ourselves.also, we should respect others as well as people around us. it reveals that everyone should have equalized freedom, no matter their differences: races, cultures, skin color, etc,. we all deserve the same privileges.