These days, my memory isn't what it used to be. Besides that, my memory isn't what it used to be.
But my incurable case of CRS (Can't Remember Stuff) is not nearly as bad as that of the exponential distribution.
When modelling failure data for reliability analysis, the exponential distribution is completely memoryless. It retains no record of the previous failure of an item.
That might sound like a bad thing. But this special characteristic makes the distribution extremely useful for modelling the behavior of items that have a constant failure rate.