We all know that there are many things unknown to all of us!
We do not know what is going to happen, next hour, day, year, decade and so on.
We do not know how the person whom you have known for years may behave in a particular situation
We do not know why do we fall ill at certain time only.
We do not know why are there certain differences between us, though we are apparently identical
We do not know the climate that would be, say a decade later
We do not know what lies in the Universe beyond what scientists/astronomers tell us, for example the exoplanets
We do not know how much of the claims of scientists (including astronomers) are really true.
So, if you find this opinion poll attractive, please do vote; If you fell like it you may post some comments too