Its all about perspective

When reading The Stranger, the character of Mersault comes off as rather socially awkward and strange, but to others such as Marie and Raymond, and even Salmano, Mersault is just a normal person. Could it be the fact that all of Mersault's thoughts, both those he acts on and those he doesn't, are expressed which makes him seem strange? If you were to meet someone like Mersault, and didn't know what they were thinking obviously, do you think they'd come off as strange?