The Power of Helium

Among other things, Mark gave me three helium balloons for my birthday.  After a couple of weeks I went to pop the balloons and throw them away.  Mark stopped me because he wanted to see exactly how long they would last.  Well, two of the balloons didn't last much longer.  Though that might have been because Mark taught Charlie how to pop them when they started floating towards the floor.  My birthday was three months ago today and there is only lonely balloon still fighting the good fight.