Hello! It's good to hear from you.
Most people feel that when the work day is done, they are done. Very few people want to continue beyond that point because they see the time they have outside of work their time. There is nothing wrong with that either. It is not because you did not want responsibility or that you never grew out of being a teenager. And having a baby as a teen is quite different than having a job you want a break from when you are 24 years old.
You were young and that may have been a small factor in it. If you did not have any other responsibilities, including a family yet, you may have wanted to enjoy yourself in your own pursuits. But again, that is not immaturity, that is just wanting to set boundaries with your job and personal life. That is something people actually need to do to deal with stress.
The only jobs that you could not expect to have a division of personal life and work are careers such as doctor, lawyer, military and police officer. Their jobs tend to be part of who they are and not just a job.