Ah, that first acquaintance. The looks, the flirting, the first kiss. The stomach knots, the heart beats, everything around you hums. You have no mind for anything else. You look forward to the next time you see him again, when he touches you again. You feel that everything is wonderful, your soul is filled with joy and excitement for what is happening to you.

Can he keep this feeling forever? To land you, no. But that’s not bad. People, relationships and feelings are ever-evolving concepts and, for everything that fades, something else comes along, many times better. One thing is certain: Each phase of a relationship is characterized by different emotions, which is why, fatally, at some point the excitement of the new will give way to something else, deeper, more essential. Or maybe not;

When the excitement starts to deflate, how will you tell if the love has gone with it?

There is a scientific term that describes the feelings of an acquaintance: It is new relationship energy (NRE) and, according to experts, it is the result of chemical processes in the brain. When you meet someone you like, there’s a burst of neurotransmitters like dopamine and oxytocin that are released in the brain, causing positive feelings, Gigi Engle, sex consultant at dating app 3Fun, explains to Well and Good. NRE is the feeling of “euphoria and overwhelming excitement that occurs when you first date someone,” adds relationship expert Emily Matlack.

But, like everything in life, it’s not built to last forever. And, as it fades, some of the original spark will disappear with it. Naturally, however, the void that will be created will be filled with other feelings, such as romance, love, respect and security. If these do not appear, then perhaps this means that along with the excitement, any prospect for a common future has died out.

Usually, the initial excitement will last just a few weeks, according to sexual health expert Zachary Zane. As this energy fades, you’ll have the opportunity to notice things you probably didn’t notice before. The flaws and quirks of your partner will begin to show, you will get to know him better and thus you will be able to understand if you really fit and want to be with him. However, if your feelings are true, then these negatives will not be enough to “break” him in your eyes. If it is, then there is not enough love to move forward together.

There is a huge difference between the initial excitement fading and the love being gone. Loss of initial energy is completely normal. But if love is lost, then nothing remains.

To understand which of the two is happening inside you, give yourself space to think. For example, think about how you feel when you make plans for the future. If you have a tendency to avoid them or they don’t bring you the expected joy, this is probably a clear red flag. Then think about how you feel when you spend time together. “If it’s something you crave and enjoy and it makes you feel safe and happy, then you know love is still here,” says Matlack.

In any case, it is useful to examine your feelings regularly. This will help you discern whether your relationship is just going through a normal transition stage, or if you are experiencing changes that are telling you it’s time to call it quits and move on.