You can't do it and be stable. That isn't to say you can't do it for short times. I only started a small software consultancy while having a day job along with

You can't do it and be stable. That isn't to say you can't do it for short times. I only started a small software consultancy while having a day job along with a wife and toddler and it was a grueling marathon. Sleep took a backseat and anything not related to work or family was pretty much off the table. You always feel like you're not putting enough time in somewhere.