As others have posted, many of us started at an early age, with our own parents and their love for camping/being outdoors. That instilled the love for being out in nature at an early age, with or without amenities.
My own journey started over 55 years ago, not long after my Dad returned from Korea. We started camping in an army surplus wall tent that served us well through my very young years. A "better" wall tent followed, plus sleeping in the back of a '59 Plymouth II station wagon, and later a '64 Plymouth III station wagon. Ahhh, the experiences of my youth!
On my own, started with a pup tent and ground mat, and cooking utensils in a box in the late 60s. Graduated to a slightly larger tent and did a LOT of tent camping. Bought a beat up old Chevy delivery van and did my own conversion of it, put in paneling and a bed platform, with a a comfortable mattress in the back. That served as my major travel vehicle for exploring Colorado after moving here in 1981 and served me well for a lot of exploring. Ran that old beast into the ground.
Later moved up to an older (68) StarCraft popup towed by a classic 74 Ford Galaxy sedan. Used that combo for a lot of cross country trips back east, with a toddler in tow! That was a challenge unto itself. Loved that old StarCraft and eventually replaced it with a more modern StarCraft popup towed with a Toyota Van (the original one and very under-powered) and a 4Runner. In between the 2 popups, had a Chevy custom van with an electric sofa bed in the back.
Hiatus in camping till the itch got too great! Bought my current Keystone Outback 25RSS and that's going to be my retirement vehicle, at least for the foreseeable future. Meets all our needs for seeing the good ol' USofA!