Illness, disablement, and death do not create misery — misery is created from negative perception. Negative perception is viewing life in an unpleasant way — and a negative outlook is counterproductive to happiness.
Many people triumph after being faced with illness or disablement. Likewise, many people triumph after being faced with the deaths of people they know. Therefore, these events do not inherently create misery, it is the way in which people react to these events that creates misery.
Although negative beliefs can seem instinctual and necessary, beliefs can be modified through immersion and repetition in sources of thought that explain and extol the new belief. If we want to believe in something new, we can seek out various sources and saturate ourselves, repeatedly. And once loaded up with ideas, we contemplate them, again and again until they take hold. And fortunately, this route is not as difficult as avoiding illness, disablement, and death.