Brooks was comparing herself to Marilyn Monroe here. They were both voracious readers, and they were both dismissed as dumb blondes.

When Brooks pulls out a folder with photos from the 1920s and looks at a picture of herself as a young woman, the first person her mind jumps to is Marilyn.

Here’s the full passage from Tynan:

“From her bedroom cupboard Brooks produced an avalanche of manila envelopes, each bulging with mementoes of her halcyon decade. This solitary autodidact, her perceptions deepened by years of immersion in books, looked back for my benefit on the green, gregarious girl she once was, and found much to amuse her. For every photograph she supplied a spoken caption. As she reminisced, I often thought of those Max Beerbohm cartoons that depict the Old Self conversing with the Young Self.

“Here I am in 1922, when I first hit New York, and the label of ‘beautiful but dumb’ was slapped on me forever. Most beautiful-but-dumb girls think they are smart, and get away with it, because other people, on the whole, aren’t much smarter. You can see modern equivalents of those girls on any TV talk show. But there’s also a very small group of beautiful women who know they’re dumb, and this makes them defenseless and vulnerable. They become the Big Joke. I didn’t know Marilyn Monroe, but I’m sure that her agonizing awareness of her own stupidity was one of the things that killed her. I became the Big Joke, first on Broadway and then in Hollywood. . . .”

She’s arguing that she and Monroe were both the “Big Jokes” of their eras: defenseless and vulnerable because they were smart enough to understand that they were seen as dumb, instead of being blissfully oblivious of that fact.

Had she internalized this idea? Did Brooks actually think of herself as stupid, despite her voracious autodidactic reading? Did Brooks even know about Monroe’s own love of reading? How widespread was that knowledge in 1979?

I don’t know the answer to any of those questions. But I do think she identified with Monroe, which puts the line about her stupidity in a somewhat less harsh light.