I know when I'm love when I actually make an effort to make contact with you (read: actually call you back when you call me... or even better... answer the phone!)
Usually once contact is made, I tend to get really quiet and shy and jittery because I'm analyzing ever single action and word I'm saying and then immediately mentally smacking myself for sounding/acting stupid.Then again this could only apply to the introverts.
I really identify with the bolded, though I will usually (over)analyze the interaction after the fact, creating a mental playback of the event to identify what I perceive as the "mistakes" I made, which typically have to do with me being extremely oblivious to social rituals and the like that are obvious to most others. I'm probably overcritical of things that are really rather minor, and I'm thinking/hoping others don't mind or don't notice to the extent I do, or fail to notice them at all.
As for the topic, to be honest I'm not sure I've ever experienced the the fullest or most genuine (consumate?) expression of love. Growing up I became infatuated with a number of girls (about 1 every two years it seemed) without ever really knowing them very well (the attraction usually amounted to constant observation...), and it certainly felt like genuine love. The euphoria, the clenching of the muscles upon seeing them, the constant presence in the back of the mind...But I didn't really
know them, and indeed sometimes after getting to know one of them better I questioned why I was attracted to them in the first place.
Now that I've actually gotten close to a girl and actually interact with her, I don't feel the things I used to, or at least not to the same extent. Maybe it's because we became friends first, and I saw her as nothing more. I think I may be getting slightly confused with my feelings toward her, as I've never had a female friend that shares so many similar interests with me.
This post by Ezra explains what I mean pretty well (the first example):
I actually shunned love until I fell in love with someone earlier this month. When last year in my first proper relationship my girlfriend told me after two months that she loved me, I thought I must by default love her too, so I told her, but I thought "if this is what love is... what on earth is the fuss about?" But then as the months drew on I began to believe it and told my best friend "when you're in love you'll know it". But even so, I still didn't love her. I had an emotional connection to her definitely, because I was distraught when we broke up.
Now I'm actually in love, it's incredible. It has shot right up my list of priorities in life, and the fact that I actually value another person almost as much as myself is exhilarating. Whereas with my ex I thought I loved her but thought the reason I never told her so with proper feeling was because that was just the way I am - emotionally detached. Now, I realise that it was because I did not love her. Who I love now I can freely tell that I love her and I feel good every time I do; I feel emotionally free and healthy. That's how you know you're in love.
I feel the same way in that I wonder "what all the fuss is about" and feel emotionally detatched (or at least I don't feel the strong emotions I did when I had fallen for girls in the past). I just don't think I've reached that point of actual love Ezra describes. I don't feel any "romantic" attraction, just mutual interest(s) and enjoyment. I suppose it's possible I'll get to that point, but the process seems off to me, as I never before made friends with someone I'm interested in before becoming attracted. I think I'll know when I'm really in love when I actually make an effort to make contact with the person instead of just letting things play out, something I rarely do. Constantly analyzing the relationship, moreso in terms of interests and personality differences than emotionally, would be another sign. In fact I do this somewhat already. Another signal is that I open up to them, feel as though I can be completely myself, and let my Ne take over; wanting to explain the intricacies of my interests and theories about things, probably at a level somewhat further than her interest and knowledge in a given topic would deem appropriate (which leads me to criticize such moments afterwards).
By thinking that way, you only give your fear more power. 
