Pretty high, chances of life getting started are lower than we can imagine based upon the evidence that we have about it. That's the surprising thing.

Imagine 256 bits of entropy, but each bit is a spectrum on which earth and life sits in a Goldilocks zone. Nudged just a tiny bit either way and life doesn't happen, regardless of the state of the other 255 spectra.

Now, I don't think it's 256 bits, but the number of factors that have been just right are way higher than you'd expect.