Is Honesty Really the Best Policy?

Ever since I was young, I have had this cliche phrase repeated to me over and over again. I have generally accepted it as truth, and therefore live my life by the mantra that being honest with people is simply the best thing to do. But lately I've begun to question this "truth", and I find my code of ethics being called into question. For starters, I've recently taken to pranking my friends over the past 8 months and found myself staring people in the face and straight up lying. The first time I did it I thought I would be struck dumb, and I could feel my insides twisting in revulsion. But the more you lie, the less you feel it. And I'll be honest, the pranks were definitely fun and entertaining. Secondly, I have found that my sometimes brutal honesty has given offense to some. I was recently asked by a friend how he could, and I quote "get girls to like him." Oh brother, if only I had the nerve to tell him the whole truth. But I did proceed to tell him what girls like in general, and his current behavior was a little less than adequate. Of course no one likes to hear their flaws, and I've noticed a little frost in the friendship as of late because hey, the truth hurts. So now I'm left wondering if my personal mantra has led me astray all these years... Maybe lying can be fun, entertaining, and even less hurtful?