Just wondering this one and would be interested in others thoughts. I have 3 boys and they have never really done organised structured activities (as in paid classes etc). The most has been swimming lessons and my eldest did a baby /toddler music group when younger. We don't do anything at weekends other than visit family, hang out at home, play football in the garden, go shopping etc. They usually have at least one friend over to play a week.
My two eldest age 3 and 5 (the youngest is a baby) can spend hours and hours drawing, playing together and reading books and comics. The stuff they come up with is fab and IMHO very creative. I was talking to another mum recently who said her kids don't sit still so they do 8 activities a week! I sometimes feel bad that my kids don't do lots of classes but then I wonder if 'neglectful' parenting might actually be helping them to be creative and able to entertain themselves?