This time I took off around a 1/4 inch of thumb meat. I sliced it so hard and so fast that I took off some of the nail, too. There was some white stuff visible - not sure what. Bone? Chopping herbs. I don't mind the pain and I can live with the awkwardness and not being able to ties my shoes or type on my phone. But it will severely limit my guitar playing for several weeks. Left hand, end of the thumb, which I use for bracing against the neck when fretting, or for the low E string when playing chords up the neck. I seem to do this to myself three or four times a year. Always chopping vegetables. Sometimes after a cocktail. I wise up and get careful for a few months, then I get sloppy and whomp, off it comes. Depressing and frustrating. Thanks for allowing me to moan.