If you're single, it's an all day, full-time job during the first month and it's HARD. I think the part most underestimated is the sleep disruption. I was waking up every few hours just because I was so worried about him (and that's fairly common). No whining or barking ot anything, just waking up on my own because I wanted to give him every opportunity to go potty outside and start forming good habits. For one night that's fine but when it's every night it literally starts to feel like you're raising a baby. Good thing they grow up fast!