All the bases about age have been pretty much covered in this thread. Kudos to the older guys that refuse to grow old! Age is just a number; if you stay in shape and are fortunate enough to be in good health, then go for it! Pursue your dreams and maintain a youthful mental attitude and anything is possible, the sky is the limit!
I just turned 66 years young and belong to a select group of guys that share the need for extreme speed and performance, age be damned! We assault the pavement and canyon roads aboard the fastest production vehicle in existance, the Suzuki GSX1300R "Hayabusa". Out of the box, 9.7 @ close to 150MPH in the quarter, 186MPH top end (restriction limited).
Gonna order up a Performance White, 401A premium pkg, 3.73 diff. and Brembo pkg towards the end of summer, when hopefully all the bugs of a new production vehicle are sorted out.
So, if you think 46 is old, climb aboard for the first 30 seconds or so of the attached video and watch the speedo go from zero to 186 in about 18 seconds (professional rider, not me, but I have seen many 170MPH stints out here in the desert). YouTube - Onboard the 2008 Suzuki GSX1300R Hayabusa