My newbie DM let me roll an intelligence check because I couldn't get something that I should have.

And I DID get it. Once she set out the clues I already had but had been scattered through a few sessions.

Turns out that our warlock is 1/4 Orc, 3/4 Eladrin. We've met one of his grandmothers. The nice one. We also visited his grandfather's grave.