I look back to when I played. It's like school. Hockey would start in the fall, and we'd play until before exams, or the end of May. Then we'd have June, July, August and most of September when we weren't doing much. The science has taught us that this allows the brain to grow. The brain wants to grow and replenish itself and heal. By playing 12 months a year, we're not giving the brain that chance to get back to where it was at the start of the previous year.
Think about a pickup truck running down a dirt road, or a farm road, or a cottage road, or whatever the case may be. If you don't pull it in for servicing every once in a while, something is going to fall apart. Sooner or later, it's inevitable that you're not going to be right there. Maybe that truck will last a long time, and hopefully it does, but I think we should look at taking better care of ourselves. Plus, you'd become a better athlete, in my mind, when you're able to work your feet in soccer, or improve your hand-eye in baseball. Everything correlates and works together, so when you start the next season you're not skipping a beat and you're actually healthier.