"Do you mind a little advice? Starfleet captains are like children. They want everything right now and they want it their way. But the secret is to give them only what they need, not what they want."
- Scotty in "Relics," written by Ronald D. Moore.
Star Trek: The Next Generation, October 12, 1992

Scotty may have spent his life being rushed through cleaning up messes that were other people's fault, but he did always did it with a passion.  There was never any doubt that, though the Enterprise could explode into a million pieces at any given moment, there was no other place he'd rather be, and the crew love him for it.

Meanwhile, James Doohan may have spent his career shouting gibberish in a bad Scottish accent, but can you name another man who single-handly inspired so many people to become engineers?  That's a solid life's work.

30.) The first rule of business is that everything takes longer than expected.  Everything.

Leave yourself longer than you think necessary, and remember, Scotty only earned the nickname the "miracle worker" by routinely tripling all of his repair time estimates.

"After a time, you may find that having is not so pleasing a thing after all as wanting. It is not logical, but it is often true."
- Spock in "Amok Time,"written by Theodore Sturgeon.
Star Trek: The Original Series, September 15, 1967

(Yeah, I learned that lesson from Star Trek, but honestly, what did you expect from a geek?)