One thing I have noticed is that the first time out an edge doesn't hold its sharpness through the shave quite as well as successively with the same sharpening but after a stropping or two. In violin making we use scrapers with knife-sharpened, very fine edges turned with a burnisher to have a slight hook (done correctly, this is barely visible and doesn't make the edge ragged; wrong, the way a lot of home woodworkers do it, and it destroys the metal at the edge and give a ragged result.) As it's used, one repeatedly straightens out and re-turns the edge hook. The first couple of times it doesn't hold the hook too well, but with successive turns it maintains much better, is sharper because it's stiffer, and long lasting. It even feels different as you turn it with the burnisher. I sense the same experience and changes over time as I'm using my razors.

Work hardening - Wikipedia, the free encyclopedia

I'm pretty sure this type of work hardening is what's happening both with scrapers, and with the slight bending back and forth of the tip of the edge that a strop probably does. I haven't seen work hardening mentioned at all with regard to razor steel.