The thing you can't let go of is gravity. The reality of gravity in writing. If someone says something really mean in a sitcom, and the next wave isn't a reaction to the reality of that, you start losing relatability. In a lot of romantic comedies, they throw out the rules of life.
However far fiction writers stray from their own lives and experiences - and I stray pretty far from mine - I think, ultimately, that we may be writing what we need to write in some way, albeit unconsciously.