I guess it also depends on the person. I am a bit of a mixed of both. Sometimes, I keep things to myself because as you said, it’s embarrassing if I end up not delivering. But there are also times when I post it on social media either to encourage others to do the same or to keep myself accountable. I think it’s a matter of finding what’s work with which endeavour.
But you’re absolutely right! The reaction we get when we accomplish something big without telling anybody… it’s absolutely priceless!
Well done for completing the marathon, Steve! :)