I saw ZNMD few weeks back and liked it. I read some reviews that made comments on the actors' performance and tried to compare the movie with "Dil Chahta Hai". All this is quite unnecessary, if we realize that we can appreciate something only by experiencing it all by itself and not in comparison with something else.
Most people dislike message oriented movies, especially if the message is delivered in a preachy manner. "Hi, cut all this crap. Give me something entertaining" is the attitude. We are so filled with our ego that it does not like if someone tries to teach things. So this movie chose the right approach of conveying the message in a subtle and mild manner. The message, as I understood, is - "Banish all fear. Live your life to the fullest." Let us think about this.
Fear is a popular word in the spiritual/philosophical circles. The great sage Vivekananda often said that the message of Vedas and Upanishads is - "Be fearless". One Upanishad even went ahead and proclaimed that only if you conquer fear you can become enlightened. Fear distances you from yourself and once you conquer it you find yourself. All joy is in finding yourself, not in finding/possessing something outside. The joy of eating the chocolate ice-cream is really in you, not in the ice-cream. So in the movie, when the three friends conquer their fears they discover themselves. And then suddenly life appears in a different light. Its now an invitation to plunge and explore. In the process, you start understanding yourself more and more, learn more and more and you grow. As a wonderful quote from T.S.Eliot goes - "We must not cease from exploration. And the end of all exploring will be to arrive where we began and to know the place for the first time".