Baby don't hurt me. Don't hurt me, no more.

I'm slightly ashamed of myself.

Love is many different things for many different people, but for me -
Love is family. Love is friendship. Love is kittens. Love is acceptance. But most of all, love is when I talk to my partner, and no matter how I felt before, no matter how sad or ill, I feel like I'm suddenly on top of the world - and I've finally found the most real love that ever could exist in my life.
Sounds soppy, I know, but I'm no liar!

Love is a chemical reaction in the brain that we interpret in a certain way and that tends to give us a buzz.

Well, what can I say? I'm just all soft & mushy inside.

Why is it that the reaction happens only when we meet certain people though?

Short answer: Nobody knows.

Long answer: it's the genetic imperative, you are attracted to features that might be advantageous in offspring. But since it's more or less impossible to understand those primal urges, and often they run contrary to popular understanding (attraction to people wearing glasses only suggests intelligence but guarantees poor eyesight) nobody knows.

Now Gildermershina mocked my response ever so slightly, but I have to say I find the idea that love is a particular chemical reaction to be utterly, utterly fascinating. Perhaps not classically romantic, but I don't see why one cannot be romantic while being interested in the cold hard chemistry of the situation going on inside our brains.

Well, "love" obviously refers to different ideas. The feeling we have for family, and for friends, and then that different feeling, romantic love. Focusing on the latter, alot of it comes down to evolutionary urges. According to something I read recently, the initial feelings you would have for someone are classed as lust, almost purely a physical connection, and sees an increase the production of testosterone or estrogen depending on gender. This can develop into an attraction, which lasts longer than lust (lust is not seen as lasting any longer than a couple of months at most), several years, but it's still temporary. This stage sees lots of exciting chemicals getting released in your head to give you a substantial natural high: serotonin, dopamine, norepinephrine & various other things. By the end of this stage you develop feelings of long-term attachment to one another, this controls different hormones. It's part of the reason why alot of relationships fizzle out after a few years, they lose the buzz of the dopamine et al and the individuals want to recreate that feeling because it is joyful. The attachment stage is more akin to the bound you will feel towards your children or parents.

As for what causes us attraction to specific individuals, well, lots of discussion on that topic in the scientific community, but one line of theory is it's simply evolutionary. As Paul said above, it's a genetic urge, you are attracted towards what you want subconciously in your children.

Keep telling yourself that ;)

(just kidding)

Hah. Well, that was more of a "curiosity slash gross-out humour like" rather than a "masturbating furiously while watching like" ;)