Lovely poem! I have to say I had no intentions of taking part in this circle as I tend to think poetry just isn't for me but... this strikes a chord. And it's much more intelligible than those sonnets we were force to dissecate in school
I thought it was a sad poem, or at least the melancholic "what could have been?" type... until I got to the last line. " And that has made all the difference." To me, this line turns the mood around: the poet is telling us that this choice of a path has shaped who he is/ what he now is doing and that it is (at least that's how I hear it), a good thing. Yes this past choice was difficult and sometimes he wonders if the other woudn't have been easier/ better. But at the end of the day, the one he took is the right one, because it took him where he is, and none other would have...
Actually, I thought that last line also felt different when reading it... I'm not sure how to explain it, or what techniques if any are involved, but it doesn't really seem to fit in with the rest: it's more blunt, less poetic. Nearly as if it had been added there later/ by someone else. In fact it's as if the poet has just snapped out of his melancholic mood and returned to the reality of his current situation.
"The end justifies the means", or the place he got to justifies the path he blindly chose to get there... It's warped logic of course, but in this case it makes perfect sense.