The body is designed to experience pain more than it is pleasure. Oftentimes, even the things that give us the feelings of pleasure can easily become pain. The warm sun feels amazing on the skin but if we bathe in it too long we end up burned. When we feel good after exercising, it's the soreness after the workout that lets us know we did a good job.
It's through stress and suffering that we grow. If you don't stress the body, use it, stretch it and work it out, it becomes weak. The muscles atrophy and our bones deteriorate. But if you work the muscles and stress the fascia till the point that you experience pain (soreness) your body adapts by becoming stronger or more flexible.
Our minds are no different. No one goes on vacation and lays by a pool all week to say after that they've grown so much as a person. It's through struggle, bad relationships, break ups, money troubles, death of loved ones, that we find our greatest opportunities for growth. .
Viktor E. Frankl said "To live is to suffer. To survive is to find meaning in the suffering."
Pain and suffering are part of life, how you grow from that pain is what makes you.