I blew a tube tonight, it went off like a gunshot. The tube was an old one, and the tire (which had a torn seam along the bead) was also on its last legs. I'd foreseen the possibility that the tube wouldn't get me home, so I'd detoured about 2km to a bike shop to pick up some tubes. Replacing the tube after the blow-up, I limped along on low pressure until the next bike shop (two in one night) to replace the torn tire.
I rode the rest of the way with filthy hands and shaking my head at how much wear and tear a bike suffers when you ride 20+ km a day.