It seems to me that my death is most likely to come from one of 2 scenarios:
1) I become fatally ill with some disease (e.g. cancer) and, after a period of time, succumb to it.
2) I die suddenly as a result of great physical trauma (e.g. car accident)
Obviously other scenarios are possible, but I think these are the most likely. In case 1 I have plenty of time to sign up for cryonics (and could possibly pay for it with a “settlement” of some sort on my life insurance). In case 2, my body and brain suffer massive physical damage, and the cryonics company probably doesn’t get involved until there’s nothing left to salvage.
In either case, no great harm befalls me for waiting—over time the process will become more plausible (or possibly even proven), or maybe it’ll be disproven, and in any event the costs will likely come down as my income and net worth rise… so what’s the rush?
Common sense works surprisingly well in some cases: even as a child I didn’t believe the “10% of your brain” thing… think about it: the only way they could know this is if someone had 90% of their brain removed and wasn’t affected… and that doesn’t seem nearly as likely as people wanting to believe that everyone has vast untapped potential.
And let’s not even get started on how/why evolution would provide us with 10x the brainpower we need… is there any precedent for that in evolution? Can cheetas run 10x faster than they normally do just by trying a little harder? Can seals hold their breath 10x longer than normal?