I got set up recently, by my grandmother of all people!

I went over to her place for lunch with my parents and as soon as I got through the door she told me she had invited Justine, a workmate of hers. The way my grandmother went on about Justine I could tell it was a set up and said so. My father replied: "You should be so lucky."

As it turns out Justine was lovely, a tall honey blonde with model's cheekbones, deep brown eyes and a warm smile. She has lived in many parts of the world, is a painter and has ambitions to be a travel writer. I found myself flirting with her, and later that night I couldn't get her out of my head. I felt all warm and tingly and started fantasising about the two of us living together in a seaside shack in Sicily.

That's when I knew...it was a crush. I had all the familiar symptoms: racing heartbeat, inability to focus, a tingling in my groin, lightheadedness and rampant fantasising. I didn't know the first thing about this woman or what she's like, and already in my mind we're going out.

According to Beverly Palmer, a clinical psychologist at California State University, "a crush is bred on lack of knowledge. It's driven by unrequited love and that unrequitedness, that secrecy, keeps it fuelled."

When you have a crush, it's important to remember that it is just a fantasy. That way you can enjoy it for what it is - a pleasant diversion. You may be thinking love, but in reality it's more likely to be lust that's fuelling your crush. And if you get too enmeshed in the crush, and can't distinguish fantasy from reality, you might be headed for heart break.

A crush can be very unsatisfying. It could end up as unrequited love. Or if you act on your crush and start pursuing the object of your desire, you might find that the actual person can't live up to the perfect image of that person you have put up on a pedestal in your mind.

So if you do decide to act on your crush keep an open mind. The object of your crush probably won't be the person you imagined them to be. But they might be an exciting proposition nonetheless.

And if you decide not to approach your crushee, just revel in the fantasy. A crush will certainly make your life more interesting. The prospect of a chance encounter makes the senses tingle.