Imagine you’ve just returned from your annual physical, and it didn’t go well. Your doctor informed you that you’re overweight and are likely to have health problems if you don’t drastically change your diet and exercise routines. To make things worse, she set a hard deadline by scheduling a follow-up appointment with a specialist. You can avoid this follow-up, but only if you make some hard decisions and change your habits in meaningful ways. So why, when you have just days to go before the appointment, will you find yourself sitting on the couch, chip bag in hand?