At work, a friend wondered what was the meaning of "learning like a mother".

I refrained from throwing him into the Internet Abyssal via "learning like a boss". Instead, I asked him what word he thought might be missing from the end of the sentence. And then I launched into this mini-story.

Dinner is to be served hot, not lukewarm.

I think this is an example of ellipsis where dropping "expected" or "going" transforms the "is" from its soft helping verb form into a harder declarative.

When you can't make sense of some construction in English, try assuming that something was dropped.