1. You're gonna love it for an instant. Then the taste is going to catch up to you and you're going to be wondering why you didn't wake up 20 minutes earlier so you'd have time to make yourself a decent breakfast. Or why you didn't wake up 2 minutes earlier so you could sit down and have a bowl of cereal.
2. You're gonna be full for an instant (maybe.) Then you're going to be really hungry and finding yourself pulling into the McDonald's drive-thru on the way to the office and wondering why you bothered to rush off to work if you're just going to waste time buying breakfast on the way anyway.
3. You're gonna be spilling that glass of chocolate milk all over you in an instant. Seriously, buddy, cup holders were not really made to hold large glasses. You think you're getting to work without it all over your suit? And when that happens, you think you won't be reminding yourself that if you had just set the alarm for 2 minutes earlier you could have just consumed that stuff in your kitchen and left the glass in the sink? That would have spared you looking like a disorganized idiot to the rest of the guys in the office AND a large dry cleaning bill.