So many of the above happenings and gear acquistions fit my own versions of game changers.
For example, since I love to bushwhack to remote Adirondack ponds and waterways, I rarely, if ever camp at open designated campsites, I had always had a hard time and would waste a long time searching for a suitably flat spot for even a tiny wedge-shaped solo tent. My early BSA long time co-instructor camping buddy changed all of that when he introduced me to Hennessey hammocks. Being off the ground, I have never slept better while camping. Now I could set up camp on slopes, over dense undergrowth with not a speck of bare even flat ground, over wet swampy land, over boulders and rocks, blowdown. etc., you name it. Now I never have to search for more than a couple of minutes for suitably spaced trees over any kind of ground. The only time I might go back to ground in a tent is if I know I will be at a place where I have to camp on open treeless ground, or especially as along the Yukon River where there are no suitable sturdy trees for support.
Years prior, five other guys at work had paddled the Adirondack 90 mile race and asked me if I would go in with them to ask a cedar strip boat builder (who is a couple of years younger than I, and I actually grew up knowing), to build for us and enter a 34' cedar voyageur canoe in the 90 mile race. That got me hooked and I have entered that race year after year since, including this year being my 28th consecutive race entry in various canoe types. Having raced the voyageur well in early years got me invited to paddle the Yukon Races as the bow paddler in a GRB built stripper voyageur canoe and the team navigator and bow stroke pacer. Five times to the Yukon so far. Quite the game changer for sure. For the first ever Yukon 1000 mile race, I home dehydrated a ridiculous rules required 20 kg/paddler (weight after dried !!) of food main meals to start in the canoe with us (we consumed only 1/4 of it in 6 days to the finish). A Nesco model 1000 circular dehydrator purchase got me there. One paddler sat out to heat water with a small propane stove to prepare meals for all without the need to everyone else to stop paddling.
At about the same time I was invited by another co-worker who was a BSA wilderness program leader to take an 8-day course to certify at BSA National Camping School as an Adirondack trek leader wilderness guide for BSA. The next year I was invited to join the permanent NCS instructor staff, where I remained teaching college age+ adult outdoor leaders for the next 30 years, easily earning my state outdoor guide's license along the way. I specialized in home dehydrated (on my 3rd Nesco) and grocery store camp meals, and most especially canoe instruction, and back country land navigation. Also, in those same early days I joined a local Search and Rescue team and the state DEC soon certified me as a SAR crew boss and land nav instructor.
My recognized expertise in land nav got me invited as a paid Subject Matter Expert (SME) part time gig working for the state teaching land nav to officers of law enforcement, SAR, and other official agencies and organizations for several years. The same facility certified me in swift water/flood rescue, Ice water rescue, and motorboat swift water technical rescue.
All life game changers for sure, with so many more if we all look deeper.