Answer:
The main difference between us and zombies
This is your stomach's way of letting you know you've neglected it.
Temporary evidence of where you've been strolling
What is often on the ground getting stepped on by others, but you donโt have to wash it because it never get dirty, in fact you couldnโt wash it even if you tried?
What can you never get rid of when you lose it?
What is always coming but never arrives?