Question

explain the line ..... and many a failure comes about when he might have won had he stuck it out​

Answer 1

this line means that it is not that a person succeed all at once

but  after  passing all the obstacles that came between him and his dream.

In hindi it is ----

और जब वह जीत सकता है तो कई असफलताएं आती हैं, उसने उसे बाहर कर दिया था |

hope it helps