Once upon a time, there was a huge stack of marbles. All spherical. Arranged particularly in an unorderly fashion. There were heaps, crests, mountains and agglomorations. All marbles were of same size, maybe same colour too. But as long as the sizes were the same, the colour didn't matter much.
The blue marble was indeed distinguishable from the rest of the lot. It was surrounded some 5-6 of others and was resting comfortably in the cusion thus formed. It was touching all those near it, in point contact. How great a pleasure was! To touch and comfort and derive comfort from those who are near you. The marble they said was happy.
As time progresses, we know that the world doesn't remain stationary. The marbles grew, shrunk in size, they changed colours and shapes. Even the container holding the marbles was having its time, dancing around, rotating, shaking, oscillating. It was pretty difficult for them marbles to retain the conformation they were initially in. The blue marble, it thought had become sad with this unwanted change.
From the comfortable seat it enjoyed for all of its lifetime, had to be changed, it had to find new mountains and thus new valleys where it can rest. It could move by itself, otherwise it will be thrown at random. The marble indeed was sad, it missed the seat. It felt something was wrong since the seat was no longer there. But soon it found a new seat, and then the cycle began, being thrown out, being welcomed and then again thrown out. And one day, the container which hosted all this drama had a leak and all the marbles fell down one by one, they touched nobody then, they gave nobody pleasure and derived the same from none.