The feelings and inner desires...
The feelings and inner desires, rather all of the innate characteristics of a human being bring about an intense form of (spiritual) movement and motion in a person, and if these emotions and feelings are not controlled and channelled in a proper manner, then truly the person would transgress many boundaries and limits.
When we look at the self-sacrifice of people during the passing of time, we see individuals who in an urge to push their own goals and aims forward, became so uncontrollable and illogical that they ended up losing their own respect and dignity just to make sure that their goals were achieved.
It is because of this fact that it is said they have true faith in the bottom of their hearts for the goals that they were trying to reach towards and their faith created such a strong sense of love within themselves that without even calculating the outcome of their acts, they ended up sacrificing everything to reach to their goals and without any control, were pulled towards reaching it.
If we see that at the final stages of their lives they even ended up forgetting their spouses and children and were still trying to pursue their goals, then it is because of this reason. Sa`d Rabi` was one of the self-sacrificing companions of the Prophet of Islam (blessings of Allah be upon him and his progeny) who possessed a heart that was overflowing with faith and sincerity.
During the battle of Uhud, he fell to the ground with a staggering twelve injuries to his body and was in a state of giving up his life when the Prophet (blessings of Allah be upon him and his progeny) commanded another believer to go and investigate the state of Sa`d Rabi` and to bring him back the real news of how he was.