OakLeaf sez:

After you run out of those, 20 miles from anywhere, an hour and a half drive from anyone who knows you, and outside of cell range, do you want to fix your tube the old fashioned way, or do you want to walk?
This is precisely the reason my father insisted that I learn to patch a tube before he'd let me learn to ride a bike. It's a safety issue as much as anything.

Also, a properly patched tube does not have a hole. It has a patch that is probably more airtight than the original tube.