Unfortunately, unless you define "head up your ass" as "listening to any other people, including probably your doctor," this is definitely not true. Most otherwise rational and well informed people still seem to be under the impression that all fat is bad.

Never met any such rational and well informed people. How could all fat possibly be bad? Cellular and organellar membranes all over the human body (and any other organism on this planet) are built from fat [1].

These membranes conduct neural signals, release and respond to hormones, participate in immune response and facilitate all types of metabolism by enabling cell and organellum compartmentalization.

Some of the fatty acids necessary for these functions are not even produced by the human body [2] and therefore must be ingested.

I think the real question people ask is not about whether fat is bad or not, but about the benefits and risks of relative proportions of fat and other nutrients.

[1] https://en.wikipedia.org/wiki/Cell_membrane [2] https://en.wikipedia.org/wiki/Essential_fatty_acid

stormbrew did say "otherwise rational and well-informed". I.e. not rational or informed in this particular matter.

Okay, s/ass/"collective ass"/. :)