Babies spend nine months growing in the womb, so it's not surprising new mums can feel a bit strange the first time they head out without their newborn.
But what happens when the opposite is true?
One new mum posted on UK site MumsNet to ask if it was "weird" that she didn't give her 11 day old baby a second thought when she went out without him for a few hours.
"I have a DD (darling daughter) who is nearly 5, and a DS (darling son) who is 11 days old. This morning [my daughter] and I went to the cinema with friends, so we were out for about 3 hours," the mum, known as Xuli on the site, wrote.
The mum explained that her son is formula fed and was left at home with her husband, adding, "I can honestly say I never really thought about [him] while I was out. It was lovely to spend time with [my daughter]."
"Reading ... about leaving babies, most people seem to say they could barely leave theirs for an hour when they were weeks old. I'm wondering now if it's weird I was so happy to leave a newborn?"
If the mum posing the question was hoping to get a wide variety of views, then she would not have been disappointed.
Most were supportive of the mother's decision. Fellow mums believed it was fine to spend time with older children while a baby is cared for by its father, even if they did not get to do that when they were new mums themselves.
"Not weird. You don't love your child less you were just enjoying your other child for a few hours," one mum commented.
"I find it weird in a 'so different from my own experience that I have to put some effort into imagining it' way, but not in a 'you are a freak and a terrible patent' way," wrote another.
"I breastfed, which probably makes a big difference - at 11 days with both of mine I was spending most of the day stripped to the waist doing skin to skin."
However, not everyone had a positive response to the mum's question.
"I think it's quite sad that at 11 days old you didn't even think about whilst away from him tbh," was one mum's view.
"Everyone's different so leaving him at this isn't weird in itself. If he didn't cross your mind at any point then I find that a bit odd. My daughter is 2 and I think about her most of the time when I'm away from her," said another.
But perhaps the most sensible responses were those who pointed out who the newborn boy was being cared for in his mother's absence: his other parent.
"He was with his dad, not a random stranger, you knew you could trust him and you were enjoying time with your daughter," one mum wrote.
"Of course it's fine to leave him with a loving dad."