@ Magrus.
Yes
I measure my life in...
Oh my, Magrus, you're in for a real treat if you've never read that poem before. Here is a link to it. It's a powerful poem with many different threads of meaning. You may well wonder why it's called a "love song". 
The opening lines are a quotation from Dante's Inferno. I don't have a direct translation, but the meaning is essentially this: "If I believed that I was speaking to someone who could share my secret knowledge with the world, I wouldn't share it with you. But since you can't share it with anyone else, I am not afraid to reveal it to you." That's not what it means literally, but that's essentially what it means.
The opening lines are a quotation from Dante's Inferno. I don't have a direct translation, but the meaning is essentially this: "If I believed that I was speaking to someone who could share my secret knowledge with the world, I wouldn't share it with you. But since you can't share it with anyone else, I am not afraid to reveal it to you." That's not what it means literally, but that's essentially what it means.