I don't necessarily agree that you need to know your parents net worth, but i do think it important you have the means to access the various accounts/insurances/other important documentation, etc so that the rightful heirs are able to deal with the estates of their loved ones (not just parents) in the proper fashion, not necessarily just the distribution of any wealth/assets but closure of accounts etc. so that, for example, utility bills don't rack up additional charges.
A vey astute post picked up from Listnerds
!CTP
RE: Know your Parents Net Worth