I'm not one to disagree with you, that you probably wasted your time in calculus, just as I wasted my time in philosophy. I don't really give a rip about Euthyphro, the Apology, etc., and certainly couldn't give a flying fig about "The Pear Tree Incident" for which everyone had to write a 5 page essay (and a disgruntled TA grading the paper took off 20% because he thought it was too long).
Most of my liberal arts courses were wastes of time (although I did enjoy theology), and the old mantras of "you're the wisest person if you know nothing at all" from PHIL 200 are absolute garbage in the real world.
Regarding calculus, though, I can't see why you would have had an extremely difficult time. Even back in 1968, I'm pretty sure you could have asked one of your dorm friends to help you out a bit.
Calculus courses, especially the easier ones (105 and 106, if I recall correctly), are set up in a way that if you had a reasonably good command of your Algebra II / Trig courses from your high school days, that anyone who at least honestly did the homework and put forth even a half hearted effort could easily get a C.
I knew of some truly mathematically challenged athletic individuals who did just fine in Calc 105, just by asking fellow dorm mates for a bit of help.
Still, I'm happy for you, that you pushed your way through Calc, and found your way to success, just as a Golden Domer should be able to do so.