Granted, but If you go too fast and run into something you die. If you start too suddenly, you die. If you run faster then a certain speed, you die. If you trip at high speeds, you die. Pretty much, if you run faster then normally possible, you die.
Granted, but one time you shrunk and then got stuck and were stepped on while leaving your house and were reduced to a flat piece of goo getting picked off someone's shoe.
I wish I could change into whatever person I wanted to.
Granted, but the person you want to change into turns out to have just been pretending to be someone they aren't, and so you become their horrible, disturbed inner self.
Granted, though in exchange to learning how to play it in the speed of a second, you lost your fingers due to burning them up so fast. Also your lungs gave in for blowing three years worth of air in a second. You died.