I knew of Perry Mason’s history but I’ve never looked into it. I love your story of watching it with your Grandpa, this type of stuff should be vital to this board, but I , myself, never had the experience. For me, Raymond Burr is the guy from Godzilla and Rear Window. I do remember that there was a question from Trivial Pursuit about the time Perry Mason lost a case, so the show didn’t completely follow formulaic TV from the era.
I really should watch Rear Window again. That's another story that I think has been copied as often as 12 Angry Men (which I just watched).
I mostly remember Burr as Mason but he also appeared in Airplane II, as a judge. I don't think I saw the original Godzilla until a few years ago and then it was a special edition DVD with the original Japanese Gojira so no Burr. I vaguely remember him from Godzilla 1985.
The formula of Perry Mason was so standard that the fact that he actually lost one case became a piece of trivia. I remember my parents telling me about it, but there was some twist like he lost but then found new evidence and won. Or his client turned out to be guilty so he lost on purpose? Something.