Why is learning the Prophet's biography not considered an individual obligation (fardh 'ayn), even though loving and following the Messenger of Allah (peace be upon him) is obligatory for the completion of faith, and this cannot be achieved except by knowing the details of his life?

The love of the Prophet (peace be upon him) is an obligatory duty for a Muslim, whether they know his biography or not. This is based on the Prophet's (peace be upon him) saying: "None of you believes until I am more beloved to him than his father, his child, and all people." And in another narration: "and his own self." Also, based on the Almighty's saying: "Say, [O Muhammad], 'If your fathers, your sons, your brothers, your spouses, your kindred, the wealth you have gained, the commerce in which you fear a decline, and dwellings with which you are pleased are more beloved to you than Allah and His Messenger and jihad in His cause, then wait until Allah executes His command. And Allah does not guide the defiantly disobedient people.'" Learning the Prophet's biography in detail is not obligatory, but studying it and delving deep into it increases and strengthens love.