ZT: Mom was the best teacher of computer science I had:

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For years I badgered my mother with questions about whether Santa
Claus is a real person or not. Her answer was always "Well, you asked
for the presents and they came, didn't they?" I finally understood
the full meaning of her reply when I heard the definition of a
virtual device: "A software or hardware entity which responds to
commands in a manner indistinguishable from the real device." Mother
was telling me that Santa Claus is a virtual person (simulated by
loving parents) who responds to requests from children in a manner
indistinguishable from the real saint.

Mother also taught the IF ... THEN ... ELSE structure: "If it's
snowing, then put your boots on before you go to school; otherwise
just wear your shoes."

Mother explained the difference between batch and transaction
processing: "We'll wash the white clothes when we get enough of them
to make a load, but we'll wash these socks out right now by hand
because you'll need them this afternoon."

Mother taught me about linked lists. Once, for a birthday party, she
laid out a treasure hunt of ten hidden clues, with each clue telling
where to find the next one, and the last one leading to the
treasure. She then gave us the first clue.

Mother understood about parity errors. When she counted socks after
doing the laundry, she expected to find an even number and groaned
when only one sock of a pair emerged from the washing machine. Later
she applied the principles of redundancy engineering to this problem
by buying our socks three identical pairs at a time. This greatly
increased the odds of being able to come up with at least one matching pair.

Mother had all of us children write mail in a single envelope with a
single stamp. This was obviously an instance of blocking records in
order to save money by reducing the number of physical I/O operations.

Mother used flags to help her manage the housework. Whenever she
turned on the stove, she put a potholder on top of her purse to
reminder herself to turn it off again before leaving the house.

Mother knew about devices which raise an interrupt signal to be
serviced when they have completed any operation. She had a whistling teakettle.

Mother understood about LIFO ordering. In my lunch bag she put the
dessert on the bottom, the sandwich in the middle, and the napkin on
top so that things would come out in the right order at lunchtime.

There is an old story that God knew He couldn't be physically present
everywhere at once, to show His love for His people, and so He
created mothers. That is the difference between centralized and
distributed processing. As any kid who's ever misbehaved at a
neighbor's house finds out, all the mothers in the neighborhood talk
to each other. That's a local area network of distributed processors
that can't be beat.

Mom, you were the best computer teacher I ever had.