This was because of the prophecy that foretold his death. However ... where his weak spot is with Annabeth, showing how much he trusts her. The Percy Jackson characters placing great importance ...

Jackson leans on his friends Grover (Aryan Simhadri) and Annabeth (Leah Jeffries) to help find it and restore order to Olympus. ForbesWhen Will New 'Percy Jackson And The Olympians' Episodes Drop?