They Use, "You Wouldn't Understand," or "It's Complicated."
Most people don't know shit about what's under that hood of that 2004 Chevrolet Impala they've had for four years. They couldn't point out the distributor from the alternator or the radiator cap from the dipstick. It's an unfortunate reality that mechanics can easily prey on. You can' trust them enough to just accept the fact that the dude can't simplify and break down what's wrong with your car for you. You're paying a lot of money to have your car fixed at his garage, so you deserve to know exactly what would happen for the fix.