What stops you signing up? If it's "cryocrastination", read this:
"I know more people who are planning to sign up for cryonics Real Soon Now than people who have actually signed up. I expect that more people have died while cryocrastinating than have actually been cryopreserved. If you've already decided this is a good idea, but you "haven't gotten around to it", sign up for cryonics NOW. I mean RIGHT NOW." - http://lesswrong.com/lw/wq/you_only_live_twice/
That may be true of the body, although our nervous system in our body is quite large, not to mention the spinal chord. But it's certainly not true of the developmental environment. For one thing, simulating that would require simulated thousands of other human brains.