Bhola and Herolal are employed in a computer hardware store as movers.
One day both of them are asked to move some computers. Herolal being energetic that day doesn't feel the computer to be heavy at all. At the same time he sees that Bhola is struggling very hard to lift his computer.
At this Herolal says, "What Bhola, my comp has 500 MB HardDisk and yours has just 250, even then you cannot lift it??"
At this Bhola thinks for a while and replies, "That's right, but my HardDisk is full and yours is empty"