One verse

Srimad Bhagavatam 11.10.18

11.10.18

न देहिनां सुखं किञ्चिद् विद्यते विदुषामपि । तथा च दु:खं मूढानां वृथाहङ्करणं परम् ॥ १८ ॥

na dehināṁ sukhaṁ kiñcid vidyate viduṣām api tathā ca duḥkhaṁ mūḍhānāṁ vṛthāhaṅkaraṇaṁ param

na
not
dehinām
of embodied beings
sukham
happiness
kiñcit
some
vidyate
there is
viduṣām
of those who are intelligent
api
even
tathā
similarly
ca
also
duḥkham
unhappiness
mūḍhānām
of the big fools
vṛthā
useless
ahaṅkaraṇam
false ego
param
only, or completely

It is observed within the material world that sometimes even an intelligent person is not happy. Similarly, sometimes even a great fool is happy. The concept of becoming happy through expertly performing material activities is simply a useless exhibition of false egotism.