This means marijuana’s effects on episodic memory aren’t uniform and certain details get left out. It may impair the spatial aspect of a long-term, episodic memory (as in where a past event occurred) but it seems to leave most of the rest intact. The effects of marijuana on memory can change from person to person and may be worsened when combined with alcohol, drugs and sleep-loss. Unlike “blacking-out” from heavy drinking cannabis will rarely give anyone legitimate amnesia, you’ll just forget some details. After waking up from a night of smoking with your buddies you’ll still have hazy recollections of everyone’s hilarious antics, but the exact location of the pizza place you ate at will always remain a mystery.