A relationship in its early stages can be an intoxicating thing. Aptly nicknamed 'the honeymoon period', this is the time where your partner can do no wrong, you can't remember ever being happier and you're convinced this person is The One.
As heady and exhilarating as this may be, the fact of the matter is, it's also unsustainable. (Which is fine. Either you break up or the relationship matures. Hey, we're betting even Allie and Noah from 'The Notebook' eased off the 'if you're a bird, I'm a bird' routine after a while.)
But for some people, this romantic interlude isn't just part of the relationship, it is the relationship. Once it fades, so does their interest, and it's back to square one with a newer, shinier partner.
Welcome to the world of being addicted to love.
"Love addiction is actually more like romance addiction, because the person is hooked on the romantic effect rather than actual love," Professor Frances Quirk told The Huffington Post Australia.
"In terms of evolutionary biology, there is a very, very strong evolutionary perspective on reinforcing couple's relationship with reproductive potential very quickly. The general idea is 'lock them in and get some babies out' -- that's basically how evolution works.
"The beginning of a relationship is always better than the middle or the end," Quirk continued. "And in part that's because it is all reproductive hormone-driven. There's a period of limerence, which is about binding you together quickly from an evolutionary perspective, so you can reproduce and then you continue to be bound to each other in the act of raising offspring."
Quirk estimates a limerence episode in most adult relationships typically lasts "between six to 18 months, unless you are in the context of an interrupted relationship, so for example if one of you was a fly-in-fly-out worker or had a job which saw you away for long periods of time. Then you might see it stretched out longer."
This period of six to 18 months is very much about reproductive biology, according to Quirk, which is why it's so enjoyable and also why we're less likely to find fault with our partners.
"It's about the raising up of reproductive hormones of both partners, and then the engagement in physical intimacy, sexual activity, sensuality, psychological intimacy, emotional intimacy -- all the things that reinforce the pattern of closeness," Quirk stated.
"But then fairly quickly, the real world sweeps in, and you have a week where you're really busy with work deadlines, or you get pregnant or you have a kid, and that biological cycle falls off.
"When we talk about love addiction, we are talking about the people who are addicted to that limerence phase. As soon as it starts to change, they ditch, and are off to find themselves a new limerence episode.
"They get so much out of that romance period, for them, that's what a relationship is. They don't want to move into the real world of a relationship, where you say things like 'my parents are coming for the weekend so we need to tidy up' -- that real world collide, they're just not interested in. They want to stay in rosy glitzy Hollywood glamour phase forever."
As such, someone who is addicted to love may find themselves nearly always on the look-out for their next partner, whether they're single or not.
"Love addicts spend a lot of their time hunting for The One," relationship counsellor and sex therapist Alinda Small told HuffPost Australia. "They are constantly seeking the perfect partner that's out there, somewhere.
"If they are in a relationship and they find that initial rush has dissipated, they are left feeling detached and unhappy. Whereas, in a normal relationship, we might describe that next phase as starting to feel comfortable.
"For love addicts, that feeling of comfort is discontent."
Quirk further points out that those who choose to stay in a relationship may feel tempted to stray in order to get that 'new relationship rush' from somewhere (and someone) else.
"It may be one of the factors that drives sequential affairs," Quirk said. "A person might seek that limerence top up by having a relationship somewhere else."
Where things get even more interesting is when you add internet dating to the mix.
"Online dating for [a love addict] is a huge attraction," Small said. "It has never been so easy to connect with hundreds of people, and location doesn't even matter anymore.
"Online dating sites are like shopping malls, with hundreds of potential partners choose from. You could window shop for hours.
"Another reason love addicts are drawn to it is because it enables them to create an online persona for themselves. They can create someone who they think would make the perfect partner.
"I'd even go as far as to say that they are predisposed to online relationships because it gives the illusion of a love life with a whole plethora of potential love mates. Things can develop really quickly and then fall apart really quickly, due to the intensity. It's a fantasy world of that rush of love."
In terms of how seriously love addiction can be classified as an 'addiction' from a scientific point of view, Quirk says that it's still up for debate. However, that's not to say the effects and consequences aren't very real for those trapped in the love addiction cycle.
"It does impair your ability to have sustained interpersonal relationships. There are negative consequences," Quirk stated. "Your drive to have the limerence boost means you may never have a satisfactory relationship, which can be very distressing."