"Can we start 15min later? I'm about to take a power nap"

Recently, I received a message around 10 minutes before a meeting was supposed to start. It said: "hey, do you mind if we start 15 minutes later? I'm about to take a power nap". I was flabbergasted for a second, and then absolutely impressed and amazed. I think this is one of the most direct and honest messages I've ever received in the work context. I love that this client not only asked for a bit more time, but was actually honest about the fact that he just really needed to take a quick break before the meeting. So, I obviously said yes – because I really did and do understand and I remember this as an excellent example for myself and how I will handle similar situations in the future. I'm not saying we should all delay meetings because we want to nap. But that it shows strength to be honest about these situations when they occur. What would your reaction be? And do you think you could be this honest in your work environment?