Answer:
You have it even if there is none.
A blue man lives in the blue house. A red man lives in the red house. Who lives in the white house?
What is it that given one, you'll have either two or none?
Temporary evidence of where you've been strolling
This heavy and ancient suit was not worn with a tie, but was always worn in battle.
If itβs information you seek, come and see me. If itβs pairs of letters you need, I have consecutively three. What am I?