 It's like you're on an ice skating rink, right, and people have been skating too long and the surface is all pitted. That's what your cartilage gets like as you get older. Then the Zamboni guy comes around, puts some fresh water and freezes it up, and you've got this glassy, shiny ice skating rink. This is what it's doing inside your knee, inside your hip. And it's turning this cartilage cell up and on, and you start making more cartilage like you did, say, 20 years ago, and you feel the difference. You may feel it in three or four weeks.