Keeping Track Of Every Detail

Do we really need to keep track of every detail?
Right now my online running log can preserve such details as: location, distance, time, pace, heart rate, which shoe I'm wearing, my weight, weather, and yes - a place for freehand notes.
But how much of our run do we really need to save?
[I have years and years of data saved as an Excel file.]
In Galloway’s book – Half Marathon - You Can Do It, he dedicates a whole chapter on the importance of journaling and keeping all the data about your run.

“The journal becomes the steering wheel that keeps you on the road of positive progress.”

I suppose someday I will look back at all those miles and details and recognize running was a big part of my life.

This site even wants you to note your Happiness...
Let’s see now before today’s run about a 3 - after my run a 7.
Pretty good for a Monday.
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