I don't think you need to age it if it's properly dehydrated, but you could just to make sure. It's recommended to keep them out of sunlight to make them last longer. If you try to get rid of too much of the "poison"(Ibotenic acid), you can also degrade away the muscimol and muscazone. High doses of pure muscimol can put someone in a coma, though, so there are different types of "poison". Some people eat the mushrooms raw on purpose to get the ibotenic acid. Apparently it's a strong neurotoxin that puts holes in the brain, but so does alcohol.

A lot of fly agaric "poisonings" are when pets or kids eat the mushrooms raw because they're so little and the mushrooms they find are often fresh, potent little caps that can be eaten in one bite. It can be quite an issue during prolific mushroom seasons.