That's superstition giving you peace of mind and a false sense of security.
There is no need to calibrate every time you fly.
Learn what calibration does and put your effort into things that matter.
I have issues with my Phantom which appeared after a warranty gimbal repair. The initial fault was a failure of the return to home function causing damage to the gimbal on landing, (possible VRS).
If anyone wants to comment on that, please do not, the DJI Website says that the RTH will return to the home point "without causing injury or damage."
After the repair the first time I powered up and most times when I fly a message pops up in the app saying to do a compass calibration, this may be before or directly after a flight. most times I fly on a property with enough cleared area to place 2 football fields with no metal or electrical objects anywhere to be seen. Of most concern is when the message pops up after powering down from a flight and when this happens it says there are no satellites being received. This problem may be the cause of the many problems I am have with this Vision Plus.
So, every time I fly, I do a compass calibration and would advise to do a compass calibration at every new site no matter the distance from the last flight.
There are so many things that can affect the flight, telecommunication towers, power lines, underground power lines, anything metal, any electric device can affect our phantoms. Be weary and do not become complacent. How many devices do you pass with your phantom just going to a flight site.
My phantom was sent away for the second time for repair and it was initially purchased on 16Jun14, the first time 3 days after it was purchased and no I was not a first time flyer, I have a modified Phantom 1 which I fly more often than the vision plus... "Not Happy Jan"
Not sure if this should be in this forum.