thermo quote

“Thermodynamics is a funny subject. The first time you go through it, you
don’t understand it at all. The second time you go through it, you think
you understand it, except for one or two points. The third time you go
through it, you know you don’t understand it, but by that time, you are so used
to the subject, it doesn’t bother you anymore. "

- Arnold Sommerfeld (a famous physicist)