Paradoxica
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I do with my own spare time as you do with yours.Your life, is not everyone else's life. Your comments so far, being on the topic of mine, should refer to every single person, not just you. I was never talking about just my own life.
And for the record I don't bother with anything else other than square roots. I don't have that much time to invest into my arithmetic tricks like you with memorising algebraic identities.