But differential calculus was not around at the time for O'Sensei to use. I suggest we use an abacus.
O'Sensei must've been really really really old when he died. I'll have to go back to scratching marks on rocks with harder rocks to calculate his age then.....
I actually have the next 4 month to review my calc. I should maybe look at diffEQs a bit, too. And thermo. What have I done to myself?