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--
The speaker half-convinces himself that he can always come back and return to the first path, the one he is now rejecting. But he knows the reality is that once you’ve made a choice, that choice takes you farther and farther down a path from which it’s hard to return and start over . 
 This could also mean that the path we choose in life is determined by chance and choice. They cannot be separated.
The Road Not Taken