There’s nothing like the beginning of a relationship. You feel high, gushy, energized, alive. You think about the other person all the time: They’re perfect! They’re adorable! They’re hilarious! And, best of all, so are you in their eyes. Cue the champagne, roses, and the chirping birds: The world is suddenly a real-life rom-com.

Unfortunately, that blissful early stage of a relationship—also known as the “honeymoon” phase—never seems to last. But why? And is there anything that can be done to keep the magic alive? Here, relationship experts share everything there is to know about the honeymoon phase—from what it is to what happens after it’s passed.

What is the honeymoon phase?

Simply put, the honeymoon phase is the earliest stage of a relationship. “In this stage, everything feels deeply romantic, exciting, and effortless,” explains licensed marriage and family therapist Pat Bathurst. “Both people may be deeply fascinated with each other and physical attraction is very high.”

This phase, which is also sometimes called limerence, is not just dreamy and euphoric—it’s biological. When we fall in love, a feel-good cocktail of oxytocin, norepinephrine, and dopamine floods our brains, lighting up the same neural pathways that are stimulated by cocaine—literally. This natural intoxication is “an evolutionary function to move us towards others,” explains licensed professional counselor Jennifer Melancon. “As social mammals, bonding, trust, and connectedness are key for survival.”

Cool, right? However, there is one not-so-charming potential side effect of all this animal magnetism: The rose-colored glasses of the honeymoon phase can blind us to what else might be going on.

“Partners might not notice dysfunctional patterns in the relationship,” says couples therapist Sara Miller. For example, we could overlook the early signs of toxic communication habits like stonewalling, or fail to notice that our new paramour flirts with everyone in sight. “Everything their partner does during the initial honeymoon phase can be seen as all good—and it may be hard to identify red flags for the future,” Miller says.

How long is the honeymoon phase?

While there’s no hard-and-fast rule, experts say the honeymoon phase can last anywhere from a few weeks to a couple of years. However, “from a neurophysiological perspective, the honeymoon phase typically lasts approximately six months, when the ventral vagal system is at its highest level of activation—meaning our ‘feel good’ neurochemicals and hormones are at their highest levels,” explains Melancon.