Stress
What's to be stressed about when you're doing what you love? Sure, we can nitpick. Everybody gets stressed out by their job from time to time, even the Oompa Loompas. And they work in a magical candy factory and get paid in chocolate.
Money will probably be the biggest stress factor for this job. Your starting salary will barely be enough to get by on, and with the high-end salaries capping around $45,000 (source), the pot of gold at the end of this rainbow is pretty small. The pressure is especially high if you own your own shop and depend heavily on money that walks in the door.
One popular stress culprit that probably won't affect you much as a furniture maker is the dreaded heavy workload. Assuming that everything's been cut properly, putting furniture together can get pretty Zen. You'll find your rhythm. Your hands will seem to know what to do without too much input from your brain. Before you know it, your work day will be done and you'll be able to punch out. Just don't punch it with that nail gun you're still holding. Snap out of that trance.