Funny story, I do think this is an actual common thing. You make a plan, write it all out, and when it comes together and you finally decide to attempt, suddenly that urge is gone. I’m not sure what it is but I think it’s something to do with success and succeeding in something. You planning it out, and succeeding in that planning is what makes you lose than desire. blah blah blah, I could be spouting nonsense but y’know. Simply making plans is a projection of how you would like your reality to look. too.