I had some "routine" blood tests on record from several months prior to taking a new medication with great potential for side effects. These tests proved that an anomaly seen after taking the new medication was probably not caused by the medication. Otherwise, my treatment might have been needlessly modified, thereby reducing the effectiveness of the new medication.
Humans are extremely complicated machines and it is almost impossible to have too much data.
I was quite sick years back (cancer). I’d be in and out of the hospital on a regular basis. I started declining blood tests because there was no need to monitor anything closely. I’m a very informed patient. I asked if I was home whether they’d be calling me in for blood tests and they said ‘no’. So I said ‘let’s pretend I’m home then’.