I am not sure if there was a 60% crash the last 100 years (with the exception of 1929+). Even in 1929 it took less than 20 years to recover.
Also, if you had the nerves to continue investing after the crash then the recovery would be much faster.
As another mustachian pointed out, you do not take into consideration the profits before the crash 
. Chances are you didn’t put a lampsum just before a 60% crash!