WHY IS HUMAN LIFE SPAN SO SHORT?

Actually it's not.

Do one experiment.

Close yourself in a room, keep all internet/computer/phone outside.

Just do nothing. Live like this for 5 days.

Your overstimulated mind will start to go crazy, and each hour will look like many hours looking at the seconds hand of the watch.

You will find out that life is extraordinarily long.

But you will want to immediately go back to your old life.

Compare the above to days when you go out with friends to watch movies etc, before you know the day ends.

Nowadays we live like this and before we know years have passed.

So right answer is we have found ways to spend time faster, the speed of life hasn't changed.

So, it's upto the person to make it fast or slow.