A poisonous gift?

Opening lines of Your Face Tomorrow: Fever and Spear by Javier Marias:

One should never tell anyone anything or give information or pass on stories or make people remember beings who have never existed or trodden the earth or traversed the world, or who, having done so, are now almost safe in uncertain, one-eyed oblivion. Telling is almost always done as a gift, even when the story contains and injects some poison, it is also a bond, a granting of trust, and rare is the trust or confidence that is not sooner or later betrayed, rare is the close bond that does not grow twisted or knotted and, in the end, become so tangled that a razor or knife is needed to cut it.

As opening lines go, it's hardly so inviting as "You must not tell anyone," my mother said, "What I am about to tell you" or Ships at a distance have every man's wish on board or even Call me Ishmael. I wouldn't want to memorize or recite or even diagram Marias's lines, but there's something mesmerizing about the way they tumble obsessively down the page, issuing an oddly compelling warning: "Tread carefully; here be dragons." Will a suit of armor and a vial of antivenin be enough?