To be aware of something means you notice it, know about it, or understand that it exists. When you're aware of a friend feeling sad, you've picked up on their mood even if they haven't said anything directly. When you're aware that a test is coming up next week, you know it's approaching and can prepare.

Being aware is different from just having information stored somewhere in your brain. Awareness means the knowledge is active and present in your mind right now. You might know thousands of facts, but you're only aware of the ones you're thinking about at this moment. When a teacher says “Be aware of your surroundings,” she means to pay attention to what's happening around you.

Someone who is unaware doesn't know about something, even if it's obvious to others. You might be unaware that your shoe is untied until someone points it out. Self-aware people understand their own feelings and how they affect others.

Awareness often comes before action. You can't solve a problem you're not aware of, just like you can't catch a ball you never see coming. Being aware means your mind is switched on and taking in what matters.