I think the writer means that (especially with the second line) that there is no right or wrong way to live life - we are not guided and everything is very confusing. This is shown by the phrase "pathless wood". I also think the writer is trying to get across that they think you shouldn't think too deeply about life - just <em>live</em>. They express this in the line "It's when I'm weary of considerations". The writer is saying that life is dangerous and cruel, too, with "[O]ne line is weeping / From a twig's having lashed across it open." The writer is comparing the dangerous, ruthless, confusing woods to life itself.
