[Ari]

Oh come on, it has to amaze you at least a little!
But yeah you're right, certain people have different thresholds and it's not uncommon for people to have a lowered threshold after certain drugs in a condition known as HPPD (hallucinogenic persisting perception disorder) where the more benign versions are literally visual static. Other drugs seem to raise the threshold. The interesting thing is that this threshold seems to be at least partly responsible for how intensely or 'where' you have the sensory experience.