As long as he is safe (since he is only 4 yrs old so playing outside with other children seems a bit young if they are not in the company of adults or in a fenced yard, etc), honestly.............
THANK YOUR LUCKY STARS!!!!
So many kids today are couch potatoes, and all they want to do is sit at home on the computer, play video games, or have such crazy and hecitc schedules with all of their activities that they DO NOT KNOW HOW TO BE KIDS anymore! I have such fond memories of childhood in my neighborhood, playing with the kids who lived near me, all during the summer ad after school. We couldn't wait to get outside and set up some type of game, etc. I rarely see any of that these days anymore. I can barely get my own kids to go out in our own yard and play with the NUMEROUS thing we have bought for them, for example swings, trampoline, climbing sets, basketball hoop, soccer goals, badmitten/ volleyball, tetherball, gold sets, bikes, scooters, motorized scooters, YOU NAME IT..... we have tried it. They go out for MAYBE an hour, and it's back in the house they come. It's too hot, or too cold. They are bored. Whatever. Then they wnat to watch Tv, play video games, use the computer, etc. Playing outside with other kids is one of the best ways for a child to learn good social skills, use their imagination, and to be healthy and burn calories. Not to mention, all of the vitamin D and fresh air they are getting. Hooray for you, like I said, as long as your child is safe, don't sweat it! Be happy! Obviously mealtimes are non negotiable, but the other thing to remember is now you know what the child loves, so you have some great currency to work with to help ensure good behavior. (taking away outside time if they don't listen, etc) Whatever you are doing Mama, keep it up because you will have a healthy child. Don't take it personal. You have an active outdoor kind of kid!