Stranger in a Strange Land -by Robert Heinlein.

A man raised by martians is "rescued" and brought to Earth. This is one of those books that stays with you. He thinks in a whole different format than earthlings do. He says that to fully understand something is to GROK it. This was a buzzword for awhile. Anyway, he has a whole different idea about society and the way human relations should work. It is an eyeopener.