I sharpen every 3 weeks or so, as I have time to dedicate- everything I have is white #1 or white #2 (although that will change very soon), and I use a handful of different knives for different purposes (primary knife is a W#1 gyuto and a W#2 kiritsuke, with less frequent use of a W#2 yanagiba), I cut on end-grain wood, and mostly veg with a bit of protein. I will say that I'm tough on knives (poor habits learned when I worked a very busy line).
I can't stand having my knives not sharp (really sharp... "OK" sharp won't do) - so as soon as something isn't feeling super sharp I'm rotating that knife out and getting it to stone when I have time. As my technique improves I'm finding that edges are lasting somewhat longer. But as Hutchla stated, I enjoy sharpening and see it as routine maintenance that keeps my kitchen in shape. It's no longer a profession for me, but as it's now a hobby it's much more enjoyable!