Initially they manage to come off as calm and charming and make a good impression, but then fall apart when the stakes get higher.The reason this happens is that when they first run into that women she's new and they haven't had time to overthink things and attach any nervous feelings to her yet.Dating advice is outside the scope of this site, with this article being a semi-exception.Over the years several women have written me to tell me reading this site has helped them understand the actions of a shy guy they were pursuing.He sees this, gets nervous, and never conjures up the guts to speak to her. He can't work up the nerve to talk to her another time.Another variation is when a guy runs into a girl, say because he sits beside her in a lecture, chats to her for a bit, and comes off well. A third scenario might be something more drawn-out, like a guy has a few conversations with a girl he never really thought of as more than someone friendly to talk to.The first is when a guy simply sees a girl around a few times and makes confident eye contact with her.She seems attracted and intrigued and like she's waiting for the guy to approach her.
Even with all of the above stacked against them, a shyer, inexperienced guy will sometimes have enough things go their way that they end up in a position where they're alone with a woman and want to 'make a move' on them (e.g., kiss them, put their arm around them, etc.).
At other time they can force themselves to do it, but they're a total wreck inside the whole time.
One problem that can plague shyer guys is that sometimes their nervousness doesn't appear when they first meet a girl, but comes back to bite them soon after.
Sometimes a guy will be able to talk to someone he's interested in, often because the circumstances put them together, so the onus wasn't on him to approach anyone.
If they like someone they'll often feel too nervous to ask them out and face the awkwardness and risk of rejection that entails.