Don't be irreplaceable, if you can't be replaced, you can't be promoted.
Beware of the light at the end of the tunnel, it might be a train rushing towards you
My boss arrived at work in a brand-new Lamborghini. I said 'wow, that's an amazing car!', He replied 'If you work hard, put all your hours in and strive for excellence, I'll get another one next year.'