i understand your line of thinking but i don't think that's necessarily true. it stands to reason that lumps and bumps can be pretty much any size ranging from "it's here, i swear" to "holy crap! look at the thing growing out of the head of that guy walking across the street!" i would say a more accurate way of looking at it is that if you have to spend more than 10 seconds trying to find a lump, it's probably nothing to be concerned about.
oh, yeah... i think we've all done that at one point or another. i'd be lying if i said i didn't go to the doctor at least once because of something concerning only to be told it's just my normal anatomy. i think our minds can definitely play tricks at us on this regard, which is why i'd say that for folks like us, if you need to spend more than a second or two looking for it, it's probably not something we need to be worrying about.
I have so many tension knots... neck, shoulders, both sides of my jaw, back of legs, upper arms... I stop counting. It don't bother me much anymore. I use my heating pad every other day. I also get a massage once in a while...which I need every day to loosen these knots. But again, they don't bother me too much.. I stretch every day as well.