Is it rather insulting or caring to recommend someone to sleep more?

I had a costumer at work recommend me to sleep more because she saw me at work the day before already, and when we talked about her work, she said she feared having to close down her shop, and I thought that was still better than family companies to get closed down after generations of people working in it. But then she thought I was too tired to understand that even if a family company would still run within the same generation, they'd have to keep it closed down for 15 years. I told her I didn't know about that. I felt slightly insulted in that moment, because that's no common knowledge. 🤷‍♂️