Amazing news for lazy people; sleep makes you smarter. Not studying, reading or revising, just sleeping, although the other three won't hurt either. A joint study conducted by Harvard Medical School and the University of Pennsylvania found that shut-eye enhances your ability to recall recently learned memories, even when those memories are challenged hours later by new information. 

Head researcher Dr Jeffery Ellenbogen says: "This shows us that sleep does not just passively protect memories, but rather, plays an active role in memory consolidation. Taking a stimulant to stay awake can help with alertness in the short term, but people really need sleep to retain knowledge and brain function at their best." Scientists at Stanford University have suggested that a more supportive pillow can reduce the breathing difficulties that can interrupt your snoozing, so a clever, memory foam pillow will let you sleep soundly enough to sound clever the next day.