I know my demonstrations won't go smoothly, so I record them as screencasts ahead of time. I still manage to bungle whatever it is i'm trying to do while recording, but a little deft editing makes quick work of silly typos and "duh" moments while I'm trying to figure out why something that ought to work doesn't.

s**lil*;  $*=join'',sort split q**;  s;.*;grr; &&s+(.(.)).+$2$1+; $; =
qq-$_-;s,.*,ahc,;$,.=chop for split q,,,reverse;print for($,,$;,$*,$/)
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