Are there times you miss your life when you were still single?

Not really that I miss the single life. It just crosses my mind sometimes, what could have been if I am still living the life I used to have. I was so carefree back then, no much worries except for myself. But when I see my kids now, I feel more than complete in an instant. The feeling is just overwhelming. I couldn't be happier with my kids and I couldn't imagine life without them.