"I've said it before and I'll say it again, if you do research you must keep meticulous notes of the inventive process."
That's actually an interesting distinction between the U.S. first to invent versus the European first to file approach to patents.
In the U.S., you do need to keep meticulous notes in order to prove you invented something first. (Not to mention making it easier on others who rely on your work to take it one step beyond or merely repeat what you've done.)
In Europe, where the first to file is more important for patent issues, there is less emphasis on keeping meticulous, witnessed lab books.