A Zen master and his students were walking in the forest and they came across a large boulder. 

On seeing that, the master asked his students, "Is this boulder heavy?"

"Yes," they replied, "it is very heavy."

The Zen master asked, "Are you sure?"

The students looked at it again and said of course it's very heavy.

And with that, the master replied, "Only if you pick it up."

https://www.linkedin.com/pulse/boulder-heavy-anjana-vinod-kumar/