Long, lomg ago, in another life, I did that. IU was a student and couldn't afford much, so I bought a Buck 112 and carried that all over WV hiking and camping for several years. Still keep one in the collection for old times' sake.
Then I carried a small CS lockback for 8 or 9 years. It was one of their early models with a laminated blade, dual liners, and kraton molded scales. I still have that one, too. One of the scales came unglued from the liner and I've had to reattach it, but I still have that one, too.
Lately, though, there have just been too many models that I'm interested in for me to carry the same thing for two years. I guess the closest I could come to that would be the Delica series that I use as a work EDC. I started out with a CF lefty D3. When the D4s came out, I switched to one of the VG10 models. When the ZDP D4s came out, I got a couple of those. It hasn't been the same knife, but it's been the same model for a couple of years now.
For personal EDC, I've carried an H&K 14210 for a couple of months and I don't see anything on the horizon that's going to replace it, but who knows what's waitin' out there?