This might seem a little Zen-like at first glance, but it’s really a very clear sentence about attitude.
Simply, your attitude determines your success…
If you truly believe you can accomplish something, you will.
If you have serious doubts, you won’t.
Coincidentally, I read this past weekend about a Gurkha, Nirmal Purja, who managed to beat the previous record of climbing the world’s 14 highest mountains (some 7 years, 10 months), doing so in an astonishing 6 months, 1 week – so not narrowly beating the record, then – despite having little mountaineering experience. He just was determined to show it was possible in a single climbing season.
A positive mindset enables you to accomplish miracles.
So, don’t let self-doubt get in the way of accomplishing your goals – set out to win!