Honestly don't' worry about it. High end GPU like the Titan X in general run little hotter than your average GPU but having said that, all depends how hot your environment is (Like bed room). How good is the case for airflow, your case fans, and does your case get really dusty? I'm guessing your saying tho it runs 65 degress C just running normal applications? (youtube etc) even then, in my opinion I wouldn't fully worry about it. Yes it's best normally having GPU for doing noting like youtube, should run around 40-50 but again, lots variables it could be. My room is nice a cool, even during summer time, and they are running at 35 but again different GPU and we have different rigs etc etc. I'm sure some people will say different but in my opinion, it's fine the way it is, I have my GPU through the years running around that temp and it's going still after 5 years.
Just need more info, like GPU load, fan speeds but also best to know your rig specs. More info the better.
Basic Solutions:
-Have A Fan In Your Room/Environment To Keep It Cool.
-Dusting Out Your PC
-Lower Your GPU Settins A Bit.
-Get Better Fans Or Add Few Case Fans.
-Lower The Resolution.
-Keep Cables Tidy In Your Case, To Maximize Airflow.
-Turn Up Fan Speeds