Oh only have no time to do what i love for the next 8 years huh? Sounds like a breeze! And that's the best case scenario, kids won't leave the house usually before 18-25 years of age.
It changes your life in a weird way. Stuff can be hard and still worthwhile.
― Woody Allen, Annie Hall
There are lot of places in the world where there is no expectation that the children will leave the nest.
The whole "I can't wait till my kids are 18 so I can kick them out and get my life back" is only a phenomenon in some cultures.