I get the same whenever I get my daily walk in. Pure unbounded epiphany of ideas and experiments, surging with creativity. I'll revisit them a few days later and for 90% of them my immediate internal response is "that sounds like a really sh*t idea".

Yea 90% is a more realistic fail rate of my 2am ideas which seem great at 2am, but then terrible a few days later with good sleep. If GP is batting almost .400 for insomnia fever ideas, that sounds pretty stellar to me.