I don't think they must necessarily "always happen"; capitalism is much more developed now, much more advanced, and the conditions for revolution are more pertinent. I think you should move out of thinking of the way hitherto "Communist" states have been thought of. If you think that the kind of society Communism wants to acheive is desirable, I would also suggest that you help research and develop ideas for how to reach it.

You may be interested in anarchist writers, or Murray Bookchin.