From Oxford dictionary:
Persist (v) : to continue to do sth, esp with determination and in spite of difficulty, opposition, argument or failure.
Persistence (n) : continuing to do sth in spite of difficulties.
Persistent (adj) : refusing to give up.
I knew some people in my life who being persistent in their lives. I admire their personalities in this. No matter in work, study, friendship, or even in love life.
No matter how difficult the situation is, no matter how much failure they have faced before, despite of those, they still never give up in giving or attaining or reaching for their goal in life.
I admit.. I am lack of this quality very very much.. I find that I gave up so easily once I found out that I surely couldn't make it or the situation made it so.
And I believe in one thing.. with their persistences, they may get what they long for, although it seems impossible in the first place.