Some of your reasoning, if you want to call it that, is so stupid I can't believe you talk yourself into believing it. This is no different than wearing a condom with multiple partners. Think of every ride as a different partner. It only takes one time and one partner to catch HIV for example, but I am sure like the millions around the world dying of the disease you can tell the "clean ones" from the "infected ones" by just looking at them.

I think this is the last of it for me in this thread. I guess I have not been reading my own signature line lately that I let myself get dragged into this one so easily.

Best of luck to you!