[dredmorbius]

And ... having developed a new hobby ...

Not all experiences are positive. A 1986 MRE prototype, tested in 2018 (32 years old at the time) is decidedly stale:

<https://yewtu.be/watch?v=qhCmUoDnzmk>

Watching a sampling of videos might give you an idea of what to watch for in terms of damaged / stale / degraded food. There's also good information on nutritional choices in emergency situations, including "metabolic water", the amount of water that's consumed or released in consumption of carbohydrates and fats (net positive) vs. protein (net negative), as well as caloric density by unit weight (4 kcal/g for protein and carbohydrate, 9 kcal/g for fats), vitamin, and fibre content.

A friend also reports that organisations often sell or auction out-of-date rations which can remain usable for some additional time.

With careful storage (cool, dark, dry place, low humidity, no degradation of packaging), emergency food should store well.