A Window Into Time

Teenage Julian has perfect recall, which means he has trouble finding his place in the world. But he really does know his own mind. So when he starts experiencing someone else's memories, which are also glimpses of the future, Julian realizes he must find out why.
It soon becomes clear that this unmet friend is in danger. And Julian resolves to do everything in his power to track down this mysterious other person - and prevent him from being killed.