One of the main things I noticed when I joined the pharmaceutical industry (other than the way my black robe itched and the way the rooster blood stained my shoes, of course) was how quickly one moved from project to project. That's in contrast to most chemistry grad-school experiences, where you end up on your Big PhD Project, and you stay on that sucker until you finish it (or until it finishes you.)

My B.PhDP. was a natural product synthesis, and I had plenty of time to become sick of it. My project seemed to be rather tired of me, too, judging by the way it bucked like a mad horse at crucial stages. Month after month it ground on, and the time stretched into years. And I was still making starting material, grinding it out just the way I had two years before, the same reactions to make the same intermediates, which maybe I could get to fly in the right direction this time. Or maybe not. . .time to make another bucket of starting material, back to the well we go. . .

Contrast drug discovery: reaction not working? Do another one. There's always another product you can be making - maybe this one will be good. Project not going well? Toxicity, formulation problems? Everyone will give it the hearty try, but after a while, everyone will join in to give it the hearty heave-ho, because something else will come along that's a better use of the time. Time's money.

It keeps you on your toes. You have to learn the behavior of completely new classes of molecules each time - no telling what they'll be like. You dig through the literature, try some reactions, and get your bearings quickly, because you don't have weeks or months to become familiar with things. The important thing is to get some chemistry going. If it doesn't make the product you expected, then maybe it'll make something else interesting. Send that in, too. You never know.