Is it possible for a tube to develop a tiny hole on its own after being carried around in a backpack for about 2 years? The compartment I stored it in has no sharp objects.

Right now, I'm hoping that this was just a bad tube and have now learned to try pumping up the tube before mounting it on the wheel.

Tubes can degenerate over time, so yes, it is possible for a tube to "go bad." I keep the tube dusted with talc in a ziplock bag in my bike bag. I find the talc helps prevent the deterioration of the tube and the ziplock bag keeps it from getting dirty or contaminated.

+1. The talc also aids in mounting the tube in the tire when you do use it.

Biggest thing that will kill a tube is UV light, which isn't the problem for most people. From there it's the tube chafing against things or even itself in your bag.

I do as the two above me do, although i tend to carry two tubes, and a patch kit. What's an extra pound or two on my already heavy steel vintage touring bike.

Thanks for all the helpful suggestions.

Now, off to buy some spare tubes.

you telling me you went two years with no flats? Thats awesome

On my commuter bike I'd gone 2 years with no flats, until earlier this week.

I always wrap the valve stem with something, like maybe Saran Wrap.. I figure the threats about the stem might be a source of irritation and storing it within my bike wedge, there is likely vibration .

I keep one new spare tube in it's original box, and one patched tube in a ziplock bag. Good idea on the talc !

>2 years with no flats?

Yep.

The streets in Irvine and especially at UCI are pretty clear of glass/etc.