I've never spent much time trying to analyze them. But they don't sound pretentious to me at all.
I spent and I think the key words are "living comes much easier once you admint you're dying". The whole lyrics is about the theme of "lack", "bliss", messages to find and something to believe, what we loose and what we create for our lives. I don't know if Petrucci had other meanings in his mind, but it's quite significant what he expresses in this lyrics. And then the key words... "living comes much easier once you admit we're dying". There's a hard message here, because death is so natural that if you want to live without fear and "easier" you have to admit you're dying. Lines in the Sand is not my favourite DT song, but it has a strong meaning.