I recently started biking again after taking about 2.5 years off. My bike has been sitting in my garage since then. I did a 30 mile ride as my first one back and I didn't replace my tubes beforehand. Everything went surprisingly fine, but the whole time I was worried about getting a flat. I did have a spare with me, but it's as old as my other tubes.
That got me thinking, how long do tubes usually last while they are in storage, both on and off the bike? Do I have to worry about dry rotting/cracking?