Sula, we will always be constrained by the theory of William of Ockham, Franciscan monk and another of those somewhat eccentric Englishmen who, around 1335 proprosed that , when problem solving, decided "Among competing hypotheses, the one with the fewest assumptions should be selected."

Occam's razor cries out for simplicity.

In modern terms, when your spidy sense tells you that, with PET 1) several legions of dots need connecting to produce a riddle wrapped in a mystery inside an inigma or 2) it never made it our of the lab, .......well......you know which one old William and Spiderman would have picked!

:-)