RE: Is it true what they say?
I do think it gets easier the more you do it. I also "tripped" over the first one. It was an old shed in an alalfa field. I have found as many as 25-30 in a year but have a buddy that is fanatical and he picked up 105 last year alone. His average year is around 70.
You will often find them in the same places year after year. Finding these "honey-holes" is the secret to growing your collection. Around here, South facing slopes with scattered brush and brome grass or switchgrass that collect the suns heat are the very best spots. Good luck.