how blood (your own) makes projects work better?

Was doing some tinkering on the boat just now that involved pulling
and twisting some tubing with a sharp burr on it... wrassled with it
for probably better'n 10 minutes watching out for that burr, and it
wouldn't budge. Once I finally stuck my thumb on it and wiped blood
on my pants leg, it practically fell apart. Thought I was gonna have to
do the same thing on the other side, but squeezed several more drops
out of the original puncture and then it gave up too