Sickness gets in the way of your body, but not your will — unless you let it. A lame leg gets in the way of walking, but not your will. Say this to yourself about everything that happens to you. You'll find that things get in the way of something else, but not truly in the way of you.
Sickness is an impediment to the body, but not to the will unless itself pleases. Lameness is an impediment to the leg, but not to the will; and say this to yourself with regard to everything that happens. For you will find it to be an impediment to something else, but not truly to yourself.