Personalized shaped computer mouse

  What if a mouse was invented that could take the shape of your hand? What I mean by that is, when purchasing your computer, you are asked to place your hand in some sort of gel that will take the shape of your hand. You will be asked to remove your hand, and as you do so, the gel will harden enough so that it doesn't change form, but not too much so that it doesn't feel satisfying to put your hand into. The professionals will then take this hand-shaped gel and wire it so that it functions just like a regular computer mouse.
  The advantage of having such a device would be optimal personalization and a more direct learning experience when using a computer.