谢邀。
一条路，左边是熊掌，右边是鱼。
喜欢熊掌的人选了熊掌，喜欢鱼的人选了鱼。
选熊掌的人又面对面包和蛋糕的选择，选鱼的人又面对粥和饭的选择，于是人流再次疏散……
走得远了回头看时，不同路上的人就是各自不同的命运。
人随时随地都在做选择，性格会决定你选哪条，而路上所经历的一切，又随时在塑造你的性格。
人又总是会选择相对最优解——比如，某些命运之路可能经济上未必合算，但会让人获得额外的心灵慰藉（安全感，舒适感，之类）。
所以到最后，人的命运，就是因为自己的倾向、性格和爱好，一路选择出来的。
所以，是的，性格决定选择，而选择决定命运，就是这样。
顺便附弗罗斯特先生的诗。在我看来，这是对性格、选择和命运最好的诠释了。
他的The Road Not Taken，就是我们因为性格而未去尝试的命运。
The Road Not Taken
ROBERT FROST
Two roads diverged in a yellow wood,
And sorry I could not travel both
And be one traveler, long I stood
And looked down one as far as I could
To where it bent in the undergrowth;
Then took the other, as just as fair,
And having perhaps the better claim,
Because it was grassy and wanted wear;
Though as for that the passing there
Had worn them really about the same,
And both that morning equally lay
In leaves no step had trodden black.
Oh, I kept the first for another day!
Yet knowing how way leads on to way,
I doubted if I should ever come back.
I shall be telling this with a sigh
Somewhere ages and ages hence:
Two roads diverged in a wood, and I-
I took the one less traveled by,
And that has made all the difference.
