No, you can use the same razor for days on end with a good strop and a refresh of the edge when needed. Having multiple blades does help extend the life of a SR tho, it allows the metal to "heal". Actually, the metal edge will deform during shaving and the more time you give it between shaves to recover the better because it will "come back" to close to it's original edge. Stropping will smooth out the little "imperfections".