PH255: Why keeping good lab records is important ...

Actually, there are many reasons. Here's another good one - the authors were forced to retract a high-profile paper after they lost their laboratory notebooks and could not reproduce earlier experiments. From the retraction:

"Regrettably, through no fault of the authors, the lab notebooks are no longer available to replicate the original experimental conditions ..."

 Another good reason is that dated & signed laboratory notebook entries can be critically important in patent cases, should you discover something useful.