Congrats on making it to 42!
I think my first game was in '65, back when Neyland was still a horseshoe. The northwest end was open and IIRC there were no buildings on the hill behind it.
My memory/impression growing up was that deciding to go to a game (from Chattanooga) was special, but something you could still decide to do spur-of-the-moment the day before. It was more about the logistics than the cost, one level higher than deciding to spend a Saturday fishing at Watts Bar.
I think that changed during the "stagflation" years of the mid-70s, when inflation was chewing up paychecks, and skyrocketing fuel costs were making travel a more significant factor. Those financial impediments peeled off a huge number of middle- and lower-middle class families from the normal Saturday Neyland demographic. (Though lower-middle class locals were still well represented, if they lived close enough to walk or take a bus.)
I remember as a senior in high school taking a date to a game in '71. Two years later, as a college student, the idea of taking a date or a friend to a Neyland game wasn't even a con$ideration.