If one have never had a sore thumb, one can not understand the magnitude of this old saying. Somehow the nail (outer edge) on my right thumb separated from the flesh so it is a SOB on contact. I guess I've never had a bummed thumb so I didn't realized until now how important the right thumb is and how much involvement it has on my daily life. It touches EVERYTHING! Have you ever tried to tie your shoes without the use of your thumb? very very difficult. Typing is a SOB too! It isn't broken so by habit, hitting the space bar always followed by some cussing.