Until last summer's canoeing trip to France I carried the same knife for nearly fifteen years - not daily, but always when on the road.
The knife is a relatively inexpensive C. Herbertz lockback with brass bolsters and brown micarta slabs. It's 6 1/4 inches long total, very solidly made, and it has been sharpened many, many times (mainly because of abuse, not normal wear).
The blade has the "Eduard Kettner" logo on it, with the words "explorer knife". Thanks to innumerable drops and throws, blade play has become insufferable, so I don't carry it any more. I would, though. It was a gift from my dad, who bought it for me in Germany, to replace a cheapo Buck 110-imitation that I had lost.
Dad also bought me numerous SAKs but somehow I managed to destroy them all. Maybe that's why I still don't have any SAKs but a Leatherman (which I just got back from service, had ALL the blades including pliers replaced, free of charge, naturally).
That small folder has been through three continents, up many mountains and at least once it probably saved my life. So maybe it's out of fear of losing it that it's now in the drawer.