19% in the linked article already think they're in the top 1%. That's not "ambition", that's just ignorance.
The article also had an interesting point as to why so many think they're in the top tiers: they're not surrounded by things they can't afford. Contrast my home state of Indiana, where I would have been hard pressed to tell you where to buy a Ferrari in the entire state, with the Seattle, WA area where I can list two Ferrari dealers within 30 minutes of my house. If the prancing horse isn't your style, there's a Lambo dealer in Bellevue. (Next door to the Rolls/Bentley dealer, IIRC.) I see multiple Teslas on the way to work, and I no longer think anything of seeing a Ferrari or Lambo on the way to work once or twice a week. I've regularly bicycled through Medina, WA (where BillG lives). I know what ridiculous wealth looks like, and I know that I'm not currently that wealthy and realize it's extremely unlikely that I ever will be. But if I lived in Zionsville, IN (which has, last I checked, the only Rolls-Royce dealer in the entire state) where a half million buys 5400 square feet and an acre in a super ritzy neighborhood, I might think I've "made it" and am amongst those in the top tier.
Anyway, I digress. There's ambition, then there's delusion.
Nobody ever ended up on top of the world by not believing in themselves.