I'm blessed to have my two young kids - at one point we thought we wouldn't be able to have any. But my god, they're sapping the life out of me. Pre-kids, I used to go to work all week and then get up early at the weekends with my cameras and try and capture some early morning shots out in the great outdoors. I loved it - the morning air, the peace, the sounds of nature and of course the light. But these days (one 4 year old, one 1.5 yrs old), I'm that exhausted at the end of a day that the prospect of ruining my sleep-in the next day (and by sleep-in, I mean 07:00...no later than that unfortunately, no matter what the day of the week is) to get out and capture some photos just doesn't do it anymore. I can't fatham the strength.
I feel that with the exception of holiday periods, my days of adventure are behind me...at least until they are old enough to come with me and trek 15 miles. So about another 9 years then!
Photographs of your kids will, in the end, prove to be more valuable to you than anything you leave the house to photograph.