There comes a time in most peoples' lives where everyone around them seems to be following the same life trajectory: meet someone, get engaged, get married, pop out babies.
That's assuming, however, both halves of a couple want the same things. After all, for some people marriage is important, while for others, the idea is claustrophobic and unnatural. But at the very least when it comes to marriage you can always get a divorce. (Sorry, but it's true.)
Deciding whether or not to have children is an entirely different story. There's no element of compromise, it's a lifetime commitment, and it involves at least one innocent party who shouldn't have to deal with your bullsh*t if you change your mind down the track.
It's also not for everyone.
So what do you do if you want kids, but your partner doesn't?
"It's the big dilemma in most serious relationships -- if to have children, when to have children, and how many," Jenny Douglas from Relationships Australia told HuffPost Australia. "It's a three-stage negotiation and probably unsurprisingly, given the answers to those questions are underpinned by so many different factors, including your own experiences with your own family.
"I find people either want to replicate their own good experience [of parenthood] or they seek to do something corrective, the opposite."
A difference in past experiences is just one of many factors which could see couples disagree on the children dilemma, but the big question is, can you move past it?
It really depends. If someone actually doesn't want to have children, probably not.
"The part of you which informs the decision of whether you want to have children or not, I guess it can transpire into being a fundamental, irreconcilable difference, because some people are so firm in their position they aren't prepared to shift," Douglas said.
"Most things in relationships you can make a compromise around, but this isn't one of them. If you are firmly in the position that you don't want to have children or don't see yourself as being a parent, that's something that can be irreconcilable."
However Douglas says she sees a lot of couples who both say they want to have children, but at different times or after they have achieved certain things.
"I see a lot of that. The attitude of, 'Yes, maybe some time in the future but not now'," Douglas said. "But unlike other life decisions there is an external factor for women especially which, unlike buying a house or travelling or other things, can put extra pressure on the timeframe of making a decision.
"Having said that, it's very normal for couples not to be in exactly the same place around that at the same time. I suppose sometimes it can be a position of having other anxieties, like lack of finances or failing to have accomplished certain things, including the clarity around the status of the relationship."
Which brings us to a good point. While Douglas notes plenty of couples fall into parenthood unexpectedly (often with great results), it's not fair to expect your partner to commit to having a child if the relationship isn't solid enough.
Sometimes it can be that couples are very well-intentioned and want to get everything all lined up -- the house, the career, everything -- but nature can have it's own timelines.
"A large majority of people want the child to be born into a circumstance where they can give them the best opportunities and best support," Douglas said. "If it's not clarified around the level of commitment, that could be a reason to want to wait a while."
But, yet again, we have to go back to the issue of the biological clock.
"It's a modern day reality. Sometimes because of the limit on fertility; if someone has an age-related factor concerning their fertility, couples can be drawn very quickly into that conversation. In that case it might have to be front and centre and a conversation that has to happen early in the piece," Douglas said.
"There's a certain imperative around that. So yes, it might hijack the normal stage. It can be really tough for people coming into a relationship with those age-related issues."
So what do you do if your partner is stalling for time but you're ready to get going? According to Douglas, it depends on how realistically achievable their goals are.
"You absolutely need to reality test that that's in fact a viable option for you," she said. "Sometimes it can be that couples are very well-intentioned and want to get everything all lined up -- the house, the career, everything -- but nature can have it's own timelines."
In this situation, Douglas recommends both parties writing a hierarchy of their values along with a timeline of when they expect to achieve them.
"Rank what is really key for them, individually, and also for the relationship," she advised. "If there big discrepancies between what your partner and you are thinking, that's a conversation that might be difficult."
If it doesn't sit as part of their core identity or core value system, by asking them to have kids you are also asking them to undergo a complete loss of self.
The most important thing, Douglas says, is that the conversation does happen at some point, and both parties are honest about their intentions. If you're not on the same page, it's also important to address that issue rather than carrying on as usual and hoping somebody changes their mind.
"I think probably one of the most dangerous things is not to address it," she said. "That idea that you're just hoping the other person would change their mind.
"It may be grounded in very sound reasons as to why they don't want to have kids, and if it doesn't sit as part of their core identity or core value system, by asking them to have kids you are also asking them to undergo a complete loss of self.
"It's an untenable compromise. It really is something that speaks to the core identity of someone -- and that's both in terms of not wanting to have kids or agreeing not to have them when actually you would love to be a parent."