Most attorneys I know keep a "legal research" file. As they have continued on their careers, they have come across numerous issues that took a considerable amount of time to research. After spending that time, in hopes of increasing productivity, the attorneys then dump the core parts of the research into a really long Microsoft Word file (or a really large folder or finder).
I don’t. Why? Because of the Brontosaurus.
There is no such dinosaur as a Brontosaurus. The term arose from a mistaken identification of fossils in 1877, later generally corrected among paleontologists in 1903. The "Brontosaurus" was an apatosaurus skeleton that a paleontologist mistakenly associated with a camarasaurus skull.
Surely everyone knows this old, obvious, easily-confirmed fact? WIRED is a tech-savvy, research-friendly magazine. In April 2006, it published "Bringing back the Brontosaurus," an article about reconstructing animals via their genes, without bothering to note the distinction.
Why? Most likely because the author learned it as a "brontosaurus," as did his colleagues. A simple Google search would have revealed the error.
And that’s why I don’t keep a legal research file: it’ll have something wrong with it. Maybe you put it in wrong, maybe you took it out of context, maybe the cases have been overturned, or maybe you messed up the first time around, too. I’ve always lost more time relying on a "research" file than I’ve gained.
Moreover, some of my best arguments come from reading recent court opinions, watching as a court grapples with an issue either similar or analogous to my own. The law is your tool – why let it go dull?