Chapter 2 · The Yoga of Knowledge · Krishna said
Bhagavad Gita 2.14 — Bear what comes and goes
मात्रास्पर्शास्तु कौन्तेय शीतोष्णसुखदुःखदाः। आगमापायिनोऽनित्यास्तांस्तितिक्षस्व भारत ॥
mātrāsparśāstu kaunteya śītoṣṇasukhaduḥkhadāḥ | āgamāpāyino'nityāstāṃstitikṣasva bhārata ||
Meaning
Contact of the senses with their objects brings cold and heat, pleasure and pain. These come and go and do not last; bear them patiently, Arjuna.
In today's life
When a bad day or a good day comes, remember it will pass, and keep your balance.