It’s mentioned that al-Hasan al-Basri (ra) was a man who was often sad, whilst Muhammad Ibn Sireen (ra) would laugh and joke (Tabaqaat ibn Sa’ad 6/128).
Our teacher mentioned something similar that Al-Hasan used to be fearful and would weep a lot. Makhul (ra) on the other hand used to be cheerful.
They were all contemporaries and senior Taabi’in from the Salaf.
Everyone has a different nature. Each person is unique. Piety isn’t necessarily always about being serious and sad.
Yes, if you’re inclined that way, that’s fine inshAllah. But as long as you’re in line with the sunnah, feel free to be yourself.