Definition of Implicit: implied though not plainly expressed
Definition of Bias: prejudice in favor of or against one thing, person, or group compared with another, usually in a way considered to be unfair
(So just put the two together)
Please can you send me a screenshot of the passage. I can't really answer it
Explanation:
Nick said it because of his previous experiences which were not so easy to handle and that have transformed his thoughts so much that he considered that his future would be same as his past. He even didnt remember his birthday, indicating that his mind is well occupied by the menacing experiences and thoughts. Since he has turned thirty so now people think its time to settle but for Nick its still a road of struggle ahead of him