Most Helpful Guy
Maybe he is just not ready or comfortable enough sharing those secrets yet? That does seem strange that he would mention that right away though. Like why say anything if he has no intention of sharing them at that moment
Most Helpful Girl
It takes a while to earn someone's trust. It would be naive for anyone to give their trust away freely. He obviously has things in his life which he only discloses to people who's confidentiality he trusts 100%
He obviously wants to tell you or he wouldn't have told you he has " secrets". It seems that he'll tell you when he is ready to.. in his own time. So be patient and respect his boundaries. It appears he wants to tell you, but just not yet.
He may fear telling you in case you judge him and start distancing yourself from him once you know. So he may need to know your personality more before he can trust that you won't be affected by what he wants to tell you.
Trusting people is one of the most challengeing tasks that people face, because betraying someone's trust is one of the most painful experiences that a person can face. He'll let his guard down with you in time.