All true, you see, but I would still contend that all can be accomplished sufficiently in the backyard, at least in mine anyways. We got bugs a plenty, we got irrigation water you wouldn't want to swim in, we got heat, we got rain (vis a vis the aforementioned sprinkler system), we got critters (well, maybe I can't count the lab as a bona fide varmint, but definitely a nuisance when camping out back, especially dealing with his doggie-bombs). Now, a little proofing of that sort goes a long ways towards telling me what I need to take on an overnight yote hunt, or deer hunt, and believe me, going to the hilltop in January to find out why the repeater went down, again is as good a cold weather test as you'd ever want, and under reasonably controlled conditions to boot. Granted mine is a rather rare circumstance not shared by the masses, but it does help to prepare me for the far away elk hunts when I am 30+ miles from nowhere and it's 5 degrees outside and snow blowing sideways.

So yes, if I can use the backyard as a decent controlled test arena, then I would have to agree that an ocassional outing into the bush appropriately equipped with both the "necessary items" and the knowledge of how to use them effectively.