Where would we be today if all the inventors and inventive thinkers had just given up? If they just said "I can't do this". We wouldn't have the light bulb, or the telephone (two things we rely on on more than a daily basis) or we wouldn't have put a man on the moon.
Gene Kranz (from NASA) wrote a book about his experience as a flight director for the space program. He talked about all the time they spent trying to come up with different solutions to all the problems they encountered. Most famously was Apollo 13. But think about it. What if they decided to just give up. If they said there are no more solutions that we can think of and let that defeatist attitude take over. That probably would have been the end of NASA and the lives of three men. But instead they persisted, working long and hard, but they finally came up with a solution.
There have been plenty of things in my past where I've given up on trying something new or different. But I have come to a realization now that I have to strike the word "can't" from my vocabulary. If there is something I want to achieve, I can; as long as I am willing to commit to it, think it through and persist. Even when it seems like there is no solution, there is, I just give up too soon.
The NIV says in Philippians 4:13 "I can do all things through him who strengthens me". I have to remind myself on a daily basis that because I have the spirit living in me, that I can do all things. I have then strength to go on, even when I feel I want to give up. I will persist. Failure is not an option.