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She likes musical patterns also.
Banker dad showed how to sharpen a metal edge on a good knife for mom;
same principal, any good knife dulls.
Metal markets can be different, but still a market.
I have had the book Trading Sardines in my library for a few years now (still waiting to be read). I asked about it back then on this forum, and didn't get much positive reviews so it still sits in my digital library collecting bit-dust.