Also, no one stays at a shelter permanently. Therefore everyone is a thru hiker.
Therefore no one is a thru hiker.
Thus we have proven that all people thru hikers and not thru hikers at the same time. This is actually quite a reasonable conclusion based on quantum theory, since it is only once a particle is observed that its properties are fixed. So until you observe the hiker, he/she is both a thru hiker and not a thru hiker. It's just like
Schrödinger's cat. If you put a hiker in a box, he/she will be both alive and dead at the same time, until you open the box. So the obvious solution is to not open the box.