I almost always give a fake smile.
Why do you give fake smiles?
Sometimes it avoids social awkwardness.
I suppose it might make it easier in social situations. But there are times when you should be honest about your emotions and not smile if you don't really feel like it.
I'm not changing my ways.
Pretending to be happy all the time might backfire because you aren't being true to yourself. Try being in tune with your emotions a little more, it might feel really nice to be honest to others.