Problems with aging Esbit tablets

Esbit tablets are popular with lightweight backpackers for cooking. Some people keep them in survival kits. Esbit claims:

When properly stored, Esbit solid fuel maintains its full functionality for many years.

I'm not sure what Esbit means by "properly stored", but I had trouble with 5 year old Esbit tablets.

Stupid Hiking Story #2

Mid-1970s, winter in Southern California, dry, warm weather in the forecast, so I decide to spend a weekend backpacking alone in Mt San Jacinto State Park, without a tent. I take the Tram to the top, and chat with the ranger while picking up my permit. He sees my giant down sleeping bag, mentions the weather forecast, and says I'll probably be sweating tonight.

Oops.

Stupid Hiking Story #1

After two hours wandering the hills trying to find a dirt road clearly marked on the map, I stumble upon it. Too late to turn around for Plan B, I forge ahead on the overgrown track, thrashing through deeper and deeper green stuff that I don't recognize.

Cue ominous music.