I learned that you should never trust someone saying "let me setup the basics for the project" if someone said that they'll probably come back with a book as thick as earth (round one) just to run that "basic" project. And yet it still won't run because errors and missing packages. Also they documented only half of the fixes they applied to get it running themselves.

Oh and then you only reached the point where you have no motivation left and only have a blank template to start.