Stress
Okay, so you turn out to be a tough boss. Deadlines are more like stays of execution, and phones either ring non-stop or not at all and it's your fault. There are computer breakdowns every day, so you have to be your own IT guy alongside being your own receptionist, marketing manager, and accountant. You eat nothing but junk food and energy drinks. You get no exercise and have no time for friends or family and no weekends.
You've got a presentation to some angels tomorrow afternoon and you just found out you lost your biggest investor. Your new patent will cost $500,000 and you have just enough money to pay for that, but not the rent.
Maybe you'd be the kind of boss who's totally chill. This boss, Melanie Mellowton, doesn't use a time clock, doesn't care if you need the day to get that mani/pedi or recharge with some quality World of Warcraft time, and loves to hand out bonuses just because everyone (you) is above average (also you). Warning: If you are planning to be this kind of boss, it would be a good idea to learn to smile when you say, "Do you want fries with that?"