Being in love, or what seems to be love, can mean that your emotions and judgments are all off. Where in a normal state of mind you would have a sense of objectivity (at least a sense of it!), once you've passed that magical barrier of "being in love" it seems that all objectivity can be thrown out the window.
Unfortunately, that means that you might sometimes miss things that you otherwise would be attentive to. Let's talk about something in particular.
So you, like me and everyone else on this planet, have needs. You do, I do, your person of the moment does, we all do.
You're dating someone and it comes to your attention that your "person of the moment" isn't fulfilling one of your needs. Rather than acting passive-aggressively and trying to get them to change their behavior, you raise the issue with them. After all, what did your mom always say - "I'm not a mind reader"? Well, no one is, so you decide to tackle the issue head-on. You raise the issue as recommended by all the experts. Not during an argument, at a time, and in a place where you both feel comfortable. So far, so good.
Then comes the pushback
You're "asking too much".
"I won't do that".
"Can't you just accept me the way I am?"
Deep breath. Don't freak out. Let's have a deeper look at these things.
Firstly, what are you asking? Your needs shouldn't be controlling or mean that the person is required to act in a very specific way. For me, for example, I'm very communicative and I like having open communication channels in my relationships. It's something I like and it makes me feel loved and safe in a relationship, especially as I am generally private except for when I let someone into my inner circle. Wanting for open and honest communication is VASTLY different from asking that my significant other tell me every little thing about their day, where they are at all times, and that they respond to my messages in a maximum of 30 minutes. You get the idea!
Once you've established that your needs aren't too much and that they do not fall into that category of "absurd" or "controlling", then it comes to asking yourself why your partner is resisting trying to fulfill your basic needs.
Well, if you're not asking the wrong thing.... then you might just be asking the wrong person.
The person who really loves you, and isn't merely passing by you in life, is going to try to fulfill those needs. As you would do for them! They're going to try to show you how much they care rather than just trying to stop you complaining for a while and then falling back into old habits. The person who really loves you will relish the opportunity to fulfill those needs - it's so important in a healthy relationship!
It's not that love is easy AND it's not that there's anything wrong with having fleeting relationships, it's just that the two things shouldn't be confused. If it's real, your partner is going to try to make you happy, as you will them. If it's passing you'll soon find out that your needs are only going to be fulfilled if it suits them.