The adage should really be "Do what you love AND excel at". If the conversation you had with your wife about books you read was very interesting, you could film it, sell it (or more likely ads around it) and make it your job.
While some passions are easier to monetize then others if you are in the top 100 people that do it, there is a good chance someone will pay you for it.
While some passions are easier to monetize then others if you are in the top 100 people that do it, there is a good chance someone will pay you for it.