My wife bought me a Garmin Fenix watch that tracks all sorts of metrics including stress, sleep and heart rate.  It's been an eye opener for many reasons. Last week I worked long hours to solve a difficult problem and the watch showed low stress, low resting heart rate. Basically I was doing what I'm born to do.
The week before I worked shorter hours, did less coding but far more task coordination. Stress levels high, resting heart rate all over the place.
I also found out that alcohol has a dramatic effect on resting heart rate.  The lesson is that Project management isn't for me and I will burn out if i choose it as a career progression option.
I've also reached the stage of life where the people I looked up to are dropping off the perch. I am reflecting on their pearls of wisdom. From my late father in law "Physical fitness won't necessarily make you live longer but it does allow you to enjoy what time you have".  From a late uncle "Do your best for your own satisfaction and self respect. To do less risks losing your self respect and once you've lost that you've lost everything". From a late friend "Most facts are actually opinions. Opinions are driven by experience and circumstance. If you can identify true facts from opinions and empathize with experience and circumstance then that is the lever you can use to move the world".
It's far easier to see stress and burn out in our friends and colleagues than it is to spot it in ourselves. A few words of honest appreciation for a colleague, or half an hour helping them out can make a world of difference to their well-being.