I will clarify [i]why[/i] the answer is yes. The question has a matter-of-fact answer, and is not a matter of opinion. The feelings of attraction that are called "love" in the sense the word is being used in this topic are actual things happening in one's brain. What makes real events so dependable is their tendency to occur whether anyone knows they are happening or not. To say it is impossible to be in love without conscious awareness of the fact is to say that the feeling itself does not exist when not explicitly declared to — tantamount to saying that the feeling does not exist at all, except as a fictitious social convention which we all agree to pretend is based on something real. Most people would be willing to reject that conclusion on the grounds of personal experience and common sense alone, and if this wasn't enough, there exists adequate knowledge of the physical brain activity that "is" love to put to rest any contrarian musings of that sort.

Even for the overwhelming majority of adults who would recognize this underlying feeling as "love" quite quickly, there remains some small period of time no matter what between the onset of the feelings and their acknowledgement/labeling where the person was "in love" but did not "know" it yet. This window could be one of mere minutes, and it would still be there. Except in the case of [i]very[/i] sentimental people who just enjoy the whole mystique of love so much that they will force themselves to play the role of an "in-love" person even when they are secretly lacking in sincerity, there is [i]always[/i] a feeling preceding the "knowledge" that it is there. And while the feeling itself may arise naturally, there is nothing in principle which forces any part of a person to subsequently declare, "That is love!" in response to it. One could go on in being "in love" without "knowing" for a long time, if they lacked the abstract concept of "love" to apply to the experience they're having. It is in fact not uncommon for adolescents who were not that preoccupied by thoughts of love to begin with to do just that when a first love blindsides them one day.

On that note, it should be emphasized that all that would appear to go into "knowing" that one is in love is linking feelings one is presently experiencing to the abstract concept "being-in-love" that exists in one's mind, built up from previous personal experience, and, originally, from notions acquired in early childhood from the observation of adults and characters in fictional stories. What you are in fact asking with this question is: "Is it possible for a human to experience what we call romantic love without going on to map the feeling onto the notions of 'being-in-love' distilled from its prior experiences and observations and then to begin reasoning about and contextualizing the feeling in terms of these notions?" The answer remains an unequivocal "yes", even if it may be difficult or unlikely for most people to actually accomplish this.

Yes, it's that glow type feeling when you're with that person. You have a constant smile going on.

The full force of the attraction may not sink in right away.

I think you know when you're in love, just some people are in denial

Yes... And sometimes you will only know it when the're gone. 🙂

It is possible to be in denial of our feelings.

Yes, and it is hard to ignore it. :/

yes it is possible

If you are lucky!

It's possible to be a lot of things and not know it. I suppose "In Love" could be one of them.

Yes it could happen

I don't think so.

I think it is possible.

Yes.