Hey bakz14 this is definitively NOT the first time I have heard something like this!
As it can affect your mind-set and make your brain swerve from the task at hand...
And make certain distances feel longer than reality when always checking the progress.
Just like counting days while in a jail cell

The difference between a good race and bad race is often staying positive during a ruff patch.
These often arbitrary numbers often cause the "how the legs feel versus the numbers" debate!
Which can instigate a premature assessment of the present and eventually a downwards spiral...
How-ever, it can be a very useful training tool.
To check training routes, gauge RPM and make sure your sticking to the workout plan.
But eventually, striving to be aware of your body will help you in other aspects.
Importantly taking rational decisions when faced with various circumstances

And that in my opinion, is what being an ATHLETE is all about!