These days, the most common question I get goes something like this: A decade ago, you told people that scalable quantum computing wasn’t imminent. Now, though, you claim it plausibly is imminent. Why have you reversed yourself?? I appreciated the friend of mine who paraphrased this as follows: “A decade ago you said you were 35. Now you say you’re 45. Explain yourself!” A couple weeks ago, I was delighted to attend Q2B in Santa Clara, where I gave a keynote talk entitled “Why I Think Quantum Co...