I started going grey really early, like early 20's, probably around 21-22 and then significantly grey especially in my temples by mid 20's.  Wrinkles though, I don't have any and I'm 40.  I do have those lines somewhat between my brows, but no real wrinkles per se.  The biggest thing I am self-conscious about though are bags on my upper eye-lids that have been forming the last few years.  I seriously think I will go in and have those fixed eventually.