I'm always upset when I see copilots doing strange and silly things, and they reply "...because I was told to do so by XXXX".
For example, keeping the left hand on the thrust levers of a 737 after takeoff up to the after takeoff ck list.
We have instructors, apparently, teaching this to new copilots!!!
Or flying the takeoff profile with the Flight Director NOT centered, because " I was told the 737 has got fixed pitch attitudes of 17.5, then 10 degrees " and blah blah...
So the guy keeps a lower pitch (by 3 degrees) and faster speeds all the way to cleanup.