My brother went to see Dad on Friday, but he hadn't been awake all day and I feel like a speakerphone voice placed next to his head would be the most irritating thing imaginable, so I said not to.
In the autumn, when I was teaching audio electronics, some of the student questions about transistors stumped me, so I called up my dad and he explained it way more clearly than the textbook, so I would show up in class the following week and on the review portion, I'd say, "my dad explained it like this". By the end of the term, one of the students joked "Can I call your dad? Do you think he would adopt me?". When one of the students from that class emailed to ask why marks were late this term and I said my dad was very ill (but the marks were in moderation and about to be posted), he wrote back straight away with well wishes. I never told dad he had a little fan club, only that I and my students appreciated his help.
He was my first electronics and music tech teacher. He drew a logic gate diagram of a RAM bit on my blackboard when I was maybe ten and explained it. When I was trying to write a BASIC program to improvise arpeggios, he explained how equal temperament worked and was different than Just Intonation (and why everything was out of tune). He was so generous with his knowledge. I still relied on him.
When his own mother stopped taking fluids, he panicked and had them given artificially. I didn't understand at the time why he thought that was a good idea. I still think it was the wrong choice, but oh my goodness, I understand it now.
I have not yet received a call.