Men and women both play their games as they do, it's kind of miraculous that either party ever end up getting together.

What women want most is obvious: love, respect, compassion, romance and attention.
What men want most is obvious: love, independence, compassion and their hobbies.

This probably stems from biological evolution, men instinctively want to avoid being tied down to one woman because it's more beneficial for them to "spread their seed". Conversely, women must foster and carry any offspring, thus the commitment is much more serious for them and they have more to gain from keeping one man. The aforementioned happens on a subconscious level.

To answer your question, men are typically aloof for any of a few of reasons:
- He's testing the waters and perhaps has his eye on more than one woman
- He's too shy to make a commitment or be honest about wanting one.
- He doesn't want a commitment because he doesn't "feel" like one at this point in his life.

That being said, I'm likely horrible with relationships considering I've never had a gf @ 24, haha. Regardless, the insight into how people behave when courting and getting into a relationship seems somewhat apparent, yet both parties are often oblivious, it would seem, to the other party's intentions/desires.