I'm the opposite of most, I went from 1 to 3 and while it was hard, it for some reason, felt way easier for me than 3 to 4. I am not sure why. 4 was a surprise, not planned, and we felt complete with 3. I'm not sure if that has something to do with it. Don't get me wrong, I love him to pieces. But I had 3 under 21 months when he was born and it was and still is full on. Having said that, you will never get lonely with 4. I really want everyone to have their own bedrooms so we need a 5 bedroom house haha.