I never thru hiked (I'm just a lowly 2000 miler) but did a lot of things differently.

I slack packed a few bits near Andover, Maine. Day-hiked a few bits in the White Mountains and near Rangeley ME. Bike-hiked all through New England. Walked Skyline Drive for a few miles in SNP, just to see what that was about, and because a lot of old-time thru hikers did that as well.

I've skied many of the ski areas on or near the AT -- Stratton, Killington, Pico, Wildcat, Sunday River, Sugarloaf. (Plus Sugarbush, Mad River, Stowe, and Jay Peak on the Long Trail.) I broke my femur skiing at Sunday River. A year later I walked 600+ miles of AT with a 40+ lb. pack and with the stainless steel hardware still in my leg.

Can't say I've aqua-blazed any part of the AT, but I've rafted on the Penobscot River, within sight of Mt. Katahdin. Climbed most of the major peaks in the White Mountains before I ever gave much thought to the AT.