re 5: Or they live in the SF/Bay Area and that one job pays them enough that they can afford to pay their mortgage (if they are lucky enough to have one), children's school/college, car, etc. and still have money left over for date night. Once all those expenses pile on, there are very few companies that will pay you enough. You aren't going to hop to a risky startup @100k/year when you have those kinds of expenses.

But then, if you finally got that job at Google, you can probably move on to wherever you want afterward no matter how long you were there.