Every night I think "hey I ought to hack on that little side project" after the 2 year old goes to bed but then the 6 month old wants to be held and cuddled and there's no way I'm telling her no so I can go work on a Scrapy project. It can wait.
As kids get older they take time differently. Just had my third kid and I notice a great difference in how time is used. My 6 year old is happy to spend time with my playing openttd (how he plays is interesting to an adult), and I go do something else at the same time. The baby needs me to hold her all the time and so I can't really do anything.