To begin with,I 'd admit that I have heard too much about "Never Give Up" and I am strongly opposed to this idea.
People like to take these 3 words as their motto when they are determined to do sth.As a metter of fect,nobody knows how long and how much should the aim cost you.If you insisted in one aim,your should find your energy being drained.Yet your success not come.What's more,things are always changing faster than you expect,consequently,your aim should be fixed accordingly.Give up one thing could benifit you more at another points.In addition,one's aim could be easily set far beyond one's ability,especially when he thinks "Never give up" means success.
To sum up,holding the idea "Never Give Up" is really unwise.Not only can it drain your energy,but make you miss other benifits as well.Therefore,my suggestion is you give up sometimes.