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
When a path is less travelled, the grass, weeds and wildflowers can grow in very quickly because they are not being trampled by the footsteps of travelers. 
 In these lines, Frost describes how – because the path he took was less travelled –  the path he took was the better path. He says that, in part, because the path was met by fewer footsteps, it may lead him to more “claim” (or, land) that could be used to build up his own property. 
 Because the speaker has not travelled the other path, however, he does not know this concretely, and thus these lines exist largely to be undermined by the next two. Through the explanation of the speaker’s reasoning for why he took the path, he shows that, on some level, he wants to pretend that one of the roads was less travelled than the other, even though it is not. 
 The speaker uses this  cognitive dissonance  to convince himself that his decisions are much more important and much better informed than they really are.
The Road Not Taken