The title is literal: ask your mother whether your business idea is good and she will say yes. Fitzpatrick argues the fault lies with the person asking, not the person answering, and that some questions cannot be answered badly.
What I did with it
I rewrote the fifteen-minute call. It used to open with what I do; now the first seven minutes are only about what has already happened inside the company: when the monthly close last slipped, how many days, who fixed it, what they did that month to cover for it. Facts with dates, not intentions.
The second change was in my own CRM: an opportunity only moves forward if the person handed over something that costs them — an hour of their time with a date on it, the name of whoever decides, or money. If they handed over nothing, it closes with the reason written down. I had opportunities that had been alive for weeks and were in fact dead, held up by nothing but my own optimism.
The third is a habit I kept: I record the client's exact words, not my summary. "Every month-end takes us eleven days" says far more than "they have closing problems", and it is also what works when it ends up in an ad.
What I left out
The book is written for someone hunting a product that does not exist yet and needs to discover the problem. I already know which problem I solve, so the open-ended exploration — twenty conversations with nothing on offer — does not transfer as written. I adapted it: I talk to people who already have the problem, and in the same call I say what solving it costs.
If you want to see where all this ended up, the maturity diagnostic is the written version of those questions.