A UX lesson I just know: It is better to have options than unchangeable defaults.

Another UX lesson: do one thing and do it well. Apparently Google forgot that. I still think it is a great one. And yes, I know it pertains to the function software plays and web empires are a different beast, but I find the poetic irony of the down the rabbit hole fiasco being related to a *nix quib delicious.

I think as a professional it's incredibly useful to have little rules like this that provide a structure out of which to make quick judgements and decisions.

But don't become complacent and let these transform into actual beliefs. There is no quicker way to kill your creativity.