I'm quite sure NRE isn't "real." Since I've been practicing poly for 10 years, I've learned to be very mistrustful of NRE. I didn't experience it with my last 2 long(ish) term bfs. But I did experience it this summer with a certain guy I only had 2 dates with. There was just something about him checking so many of my "I love this attribute" boxes. I wasn't obsessive, I didn't want to stay up all night talking, I just really really wanted to get to spend more time with him. It was really weird! Out of character for me, seeing as I am in my 60s and have been through the mill with relationships for a long long long ass time.
Sadly this guy realized his other newish gf wasn't OK with him seeing me and he chose her over me, for various reasons. It was his first attempt at poly and he couldn't hack it. I was so crushed and even spent a day crying. Silly me! I am way too old for this. I talked myself out of it pretty quick, knowing it was ridiculous to have such a crush after only 2 dates. (And then after 2 months I was healed... and THEN he had a problem with his gf and texted me telling me they broke up, and did I want to get together?, and then he didn't talk for 3 days, and then he finally texted to say they got back together. Which was a REAL boner killer, and showed me my NRE for him wasn't an indicator of real compatibility at all. Obviously he is way too wishy washy, and a people pleaser, and I really don't like that in a person.)
It was definitely NRE, not "love." I agree love comes after much time spent together, overcoming relationship issues, supporting each other through life struggles, cooking together, sleeping together, shopping together, helping each other with projects, seeing how they interact with others you meet (waitstaff, their friends and family, your friends and family, even acquaintances).