Don’t memorize anything. Just know what they are and everything there after should be intuitive. For example, if you know how to set up a bull spread- you should know how to find its ending value by common sense as opposed to some “ending value” formula you memorized. Fwiw, I find the same with the tax formulas. They’re very intuitive, so as opposed to straight memorizing just understand what they are (are you compounding before or after the tax, etc). Just my $.02USD.
I agree with the monkey…if you can have a good grip on the concepts behind the formulas, you can just think through them without having to straight memorize. Goes for both tax and these deriv formulas. For the options, would have to probably memorize the positions that make up the different spreads - I know I will. But if you can understand the cost/payoff for the individual positions, you can arrive at profit/breakeven or whatever else you have to figure out by thinking through it.