Most humans are not designed to handle the Truly Big Picture
This is why I think the next step in human evolution will be a very radical change, not just a larger brain or extra fingers or something like that, but something that we create, namely AI.
It is likely that the first encounter of an ETI from beings of this world will be by two AI. Not only are we still infants when it comes to exploring the Universe, but it is possible that all the "true" intelligences out there are so far beyond what we expect that we can neither recognize or communicate with them, nor do they likely feel any need to talk to us.
See Robert J. Bradbury's discussion here on Matraishka Brains for more information:
http://www.aeiveos.com/~bradbury/MatrioshkaBrains/index.html