What is the principle behind this?

When Zhang Chaoyang had money,
his yacht was called Happy.
Sanya's sky and sea were one color,
semi-naked photos on the cover.
......
He bought everything he could buy,
played everything he could play,
then he became depressed.
Later, people saw him again,
in a live broadcast room,
his hair messy,
his shirt wrinkled,
sweating profusely.
Maxwell's equations were written on the blackboard,
no yacht, no crowd,
but he was very happy,
even though at this moment, only a physics problem remains.