You know whats the best? It's having an amazing immune system and not getting sick very often. 
QFT
Haven't puked from being flu sick since I was probably 16. Now twice that age. Get a runny nose/sinus headache thing once in the fall/winter and once in the spring and that's it. Working on the tail end of one right now.
Had one really weird one a couple years ago. Got up and walked to class and felt fine. Walked in the door to class and felt fine. From between the door and my chair, maybe 15 feet, I felt the sudden urge to puke. So I set my books down and turned right back around and headed toward the bathroom. Did my business and felt fine the rest of the day. Hadn't had anything to eat since supper the night before and hadn't been drinking. Weirdest thing ever.
But when I miss work for being sick, its been because I was sick. Missed a week for appendicitis a few years ago and another time got a viral infection that was absolutely horrible. Missed work for 3 days one week, was sick all weekend, and was missed the first two days of the following week. Was chilled with a pounding headache, so I'd take an aspirin. The headache would be gone, but my chills spiked my fever up close to 104 and I would be sweating like crazy. Went back and forth like this for days.