The problem is that almost everything is simple once you understand it. Once you understand something, you think it's pretty simple to explain it.
On the other hand, people say "it's actually pretty simple" to encourage someone to listen to the explanation rather than to give up before they even heard anything, as we often do.
On the other hand, people say "it's actually pretty simple" to encourage someone to listen to the explanation rather than to give up before they even heard anything, as we often do.