Mastered as in I could teach it to others, and assemble many complicated rules for many complicated patterns.

I am always impressed with folks that retain it.

I would a ton of it for a month or two, and then do nothing with it again for more than a year or more.

It takes a lot for permanent burn-in for me. That’s the curse. The blessing is that I learn very quickly.

Waterfall: Spend 10 years compiling written functional and technical requirements. Cancel the program due to budget overrun.

Finite rules for perfectly sifting infinite options

I mastered and forgot almost entirely RegEx several times now