Agreed:
That wasn't the question. Sure, if he sterilizes his walls, furniture, and everything else he uses for the rest of his life he will be "vulnerable" when a sterile environment is not available. A phone is an item that is put in your pocket, held in your hands (and anyone you might share it with), and then pressed towards your face where it is exposed near the mouth, nose, and ear.
I use alcohol to clean my phone at least twice a week. Not to get rid of germs, but to cleanse the oily residue that builds up by handing the phone. I also do this with my mouse and keyboard. You're exposed to so many microorganisms that disinfecting a few objects, even on a daily basis, only makes up a miniscule amount of exposures. It does not 'weaken' your immune system because the T-cells have already been made to respond with antigen-specific proteins-even upon re-exposure to a specific ailment. Disinfecting any surface, even for long periods of time is not going to suddenly make them relinquish their 'memory.' I must assume then that 'weaken' was not the word you or anyone else was looking for. Rather, the pathogens will not contribute to their 'memory.' Even so, you must consider the number that enter your system; this number is far less than you might expect.
