Real or fake?

I read a saying this morning: "Fake it, till you make it". It was in the latest edition of the Positive Thinking magazine.

I have mixed thoughts on this, I believe one should be as true to others as they are to themselves, however sometimes the truth can be harsh, is it ok to fake it then. Is it really possible to fake it and finally end up liking whatever it is that we were faking?

Of course, in the story this saying was taken from, a mom really tries to make it with her son's new girlfriend whom she can't warm upto much. How does one face the fact that our loved ones bring all kinds of friends home. I often ask myself can I really be nice, be kind, be warm to them, faking it, until I really get to know them, and figure out why exactly my loved one thought these people are worth their time in the first place. Or should I let my criticism of them, and judgement towards them spill out?

Any thoughts on this anyone?