How do I make up for wasted time?

Have you ever had one of those days when you feel as though you have wasted your time/life away? That usually happens when you find yourself with a group of people whose conversation made you realise how little it is that you know. And how essential those knowledge and current affairs actually are. What a "frog in a well" you have been all this time. That is exactly how I feel right now. I'm very annoyed at myself for sitting in my comfort zone and forgetting how unknowledgable I really am, and not realizing how precious time really is. Suddenly I see the world as a buffet spread of knowledge, and I feel as though I have been walking around aimlessly all this time, vaguely acknowledging the existence of information, but never quite actively digesting it. I hate to remind myself that I've totally cut myself off from world affairs ( though, have I ever connected to begin with? ) and that I've just been concentrating on my narrow-minded viewpoint of what I deem as important all along....

It's just terribly disturbing because only you yourself are fully aware of how you could have spent your time more fruitfully...and there's also that mild panic as you realise that such awareness does not signify the ability to throw away your old lifestyle and habits easily... in fact, there is the danger of losing sight of the big picture once you are caught up with assignments and tests...