The Noble Shaykh Rabee al-Madkhalee (may Allah preserve him):

From the signs of happiness is that you have a concern for the truth, search for it and are happy when you have been alerted to your mistake.

Source: Marhaban Yaa Taalibal-‘Ilm pg. 262

Translated by Abu Yusuf Khaleefah
24th of Rabee’ ath-Thaani, 1436 H (02-14-2015)
Masjid Nur Allah, Queens, NYC

Original Arabic