Aloof or shy? There's a difference. Aloofness can be misconstrued as shyness or initial nerves and signal the wrong message to a guy.
For some, experiencing intense chemistry in a man's presence can make a woman feel naked, bared, hyper aware of her body, its arousal and sexuality - and can cause her to feel shy despite the pleasant physical sensations. It is why most initial dates include drinks - to erase some shyness or inhibition.
Unfortunately, shyness easily comes off aloofness and sends the exact opposite message of what a person is actually feeling towards another: when you want the person near you and talking to you; your behavior tells another story.
Or maybe it can be a case of once bitten, twice shy. :-)