The genetic lottery. A seven footer has a significant chance to be a basketball player. Doesn't mean that anybody else can't be, but being 7 feet tall gives you a leg up on the competition.
To be the best ___________ we can be. Mark Twain wrote volumes at the end of his life on the 'nature of man'. He wrote that man can't change tendencies any more than brass can become steel.
Work on your weaknesses and your strengths. Imagine that. Sorta like 'buy low, sell high'. Very good advice.
And take responsibility for your own condition and position. It's your job to maximize your opportunities and improve your position.
I'm just patiently waiting for fat, bald and old to come into vogue.