@oristarA,
It's well known that the faeries steal children in Ireland and in other northern European culture. Fairy children are said to cry a lot, so the fairy parents or royalty will take a human baby or trick a toddler into following them and then leave a changeling (a fairy baby) in their place. Mother knew something was wrong when junior started to cry.
Perhaps the idea for Pan came from the Faeries, but not the other way round. This stuff is older than the hills. Superstitious minds.
There are all kinds of rituals done to appease the faeries to this day in Ireland.