In 1881 Louis Pasteur injected about 30 animals with a live/active strain of anthrax. Half died. Half survived. All of the animals which had been vaccinated previously were the survivors. The non-survivors had never been exposed to the weakened bacteria which Pasteur prepared for the other group.
In order to survive an all-out assault by one of the deadliest diseases, all these animals needed was some exposure to the battle yet to come.
Life is like that. You won't become more prepared by avoiding anything which resembles the very real threats and challenges you'll inevitably face.
Avoidance creates a false sense of resilience. It also creates a false historical narrative: "I've never been sick/stressed/challenged/setback/injured BEFORE ______ (fill in the blank with some non-causal but recent scapegoat here)." No. No. No. You were just training yourself to get weaker and weaker and weaker through avoidance; and the odds finally caught up with you. They always do. They always will. Be thankful for the extreme rare luck you had beforehand. And that's all it was.
“But my knee never bothered me before,” they say. Uh huh. Did you train the knee to become better, or did you avoid training it to become better? Why the surprise? “Getting old sucks,” they say. Uh huh. Did you utilize the passage of time to become better? Or did you utilize the passage of time to avoid getting better? No surprise. “Getting old” is inert and just the passage of time. How did we utilize it?
So we prepare. We get a taste of stress. We get a touch of pressure. We lift heavy weights now, so we can get up out of a chair in 50 years. We walk a little today, so we can walk a lot tomorrow. We fast a little today, so we can be tough in the face of no food some day.
Many of the sufferings we endure today have nothing to do with recent events. Some are random. Many are from our own insistence on living too comfortably before, in our little bubbles, with too few challenges. A challenge comes, and we are underprepared or unprepared.
Moreover, be mindful not to conflate the unrelated. Insurance isn't assurance. Infection isn't affliction. Preparedness isn't persistence.
We reduce or amplify risk. We never eliminate it, nor do we guarantee success.
Exposure prepares￼. Infection is succumbing to external antigens. We reduce (not eliminate) the risk of succumbing to powerful antigens by exposure to weak but related ones. We don’t reduce risk by becoming overwhelmed by affliction.
Cancer is the proliferation of our own cells, ones with severe error due to long accumulated damage. You can't eliminate the risk of accumulated damage by accumulating too much damage on one day.
Infection is analogous to sparring. Affliction is analogous to accumulated fighting injuries. Someone who's logged 10,000 hours of sparring practice improves his odds (not guarantees wins) in fights. Someone who has accumulated two broken legs, two broken arms, ACL tears, 47 concussions, has reduced his chances of winning (but still not guaranteed to lose).
Prepare. Don’t simply persist. Embrace. Don’t simply avoid.