Then how come whenever I castle, my opponent still makes moves?
CASTLE!

Castling is vastly overrated
I learned this when I first began playing chess. The book I purchased to learn chess was only 120+ pages and it was definitely limited. It had three pages about the value of castling, and the largest part ofpages was diagrams, and not a word of how to destroy a castle. Thus, I thought once I had castled the King was safe. Some things just need to be learned through experience. As soon as I played someone that knew how to wreck my castle I began learning that castling is vastly overrated.

ivandh
(Save the Wales)
"While you take in hand to school others, and to teach them by what name a whale-fish is to be called in our tongue leaving out, through ignorance, the letter H, which almost alone maketh the signification of the word, you deliver that which is not true." HACKLUYT
I read it in Moby Dick.
Just a reminder for all of you to castle.
Remember, castling wins chess games!