Just remembered this really cool riddle and I figured I'll post it here for convenience. You can post your own riddles here, however, once there's more than one riddle, it might be a good idea to quote it while answering, to prevent confusion regarding which riddle is being answered.
My riddle is as follows:
Let's suppose you have been diagnosed with a deadly illness and only have a few months left to live. You're offered a chance to participate in an experimental treatment that will save your life. You're given two jars, each containing a hundred pills. Both kinds of pills look, smell and taste exactly the same - there's no way to tell the difference. You have to take two pills from each jar every day until you run out of both, after which you will be cured. However, if you mix it up, you die. You do as you're told until, two days before the end of your treatment, you accidentally knock over both jars and the pills get mixed up. What do you do to complete your treatment and not die?