I got a flat yesterday... rode over to a nearby park for a walk, when I got back to my bike, front wheel was flat. So I found some nice shade under a tree, changed the tube, and headed home. Turns out the leak was at the joint between the tube and the stem, which is unrepairable. Then while topping off the tire with the spare tube in it, the Presta nut broke off, and the valve core isn't removable.
So, two tubes go into the "bad tubes" box, for use as bungee straps.
Admittedly, I hate Presta valves. I understand why they exist, and they're necessary on one of my bikes because it has really skinny rims, but still,

. I've never had an un-repairable failure on a Schrader valve tube. Like 1/4 inch plugs for speakers, none of the current standard valves would exist today if they didn't have historical inertia. The computer programmers call it "technical debt." Something you keep paying for because of a decision made long ago.