In physics, friction is the resistance that one surface or object encounters when moving over another. In finance, Work Friction is the resistance encountered when turning your time into money.
Work friction is the sum of all expenses you incur simply because you have a job. This includes:
Most people only look at their net pay. However, your "Profit" is actually your net pay minus your Work Friction. If you don't calculate these costs, you are making financial decisions based on a number that doesn't actually exist in your bank account.
The goal of Life Time Costs is to help you minimize this friction, so you keep more of your life and more of your money.