I can answer it. I don't know everything. There are things I don't know.
All knowledge is actually based on belief. A true scientist wants multiple confirmations of a result of an experiment in order simply to increase the
probability that another repetition of the experiment will give a similar result. A true Christian also realises that now we can only know in part. The truth is bigger than any of us, and I can only ever get a limited perception of part of it.
There are things I don't know that I don't know.
There are things I know that I don't know.
There are things I know that I know.
There are even things that I don't 'know' that I know.
Then there are things that I think I know but don't really.
And there are things I pretend not to know which I actually know very well (but refuse to acknowledge to myself or others).
As with most adults, when I hear some new thing ("knowledge"), I automatically and subconsciously weigh it against what I "know" already, with a preference for filtering and adjusting the new knowledge to confirm my existing "knowledge" (actually more a point of view). Not to do so would be naive and lead to serious discrepancies in my thinking and logical processes over time and from subject matter to subject matter. When I cannot make the new fit the old I generally go into an uncomfortable process of adjusting the sum total of my "knowledge." This takes a deliberate effort of the will because it implicitly suggests that somewhere in the past I have made some incorrect assumptions and come to some incorrect conclusions.
My experience running training programs over many years for highly educated professional people is that most reasonable and thinking people will recognise that this is also true of them. However, I know of people who are not willing to admit that they have ever been wrong, and therefore cannot be comfortable with accepting something that is contrary to what they think they "know."
So where is all the intelligent life in the universe (other than on earth)? We don't know. We don't even know if there are other material/bodied life forms. And we know we don't know. But since the chances are not beyond the possibility that there are, we would like to know. Irregardless of space or time. Or of whether or not we are prepared for the answer. We haven't even got a consistently accepted definition of life.