Constant: Why is Des IMPORTANT to Daniel

Why is Des important to Daniel? Does he remember a man who came from the future and gave him the info he needed for consciousness time travel (creating a paradox)?

Constants have to be important to you. They have to be in the period you go and the period you are. You don’t need physical contact in both periods (Des only talked to Pen on phone).

Des is Daniel’s constant. Daniel was ‘off’ when he ‘first’ came to the island so couldn’t have ‘met’ Des yet, despite he being Dan’s constant. (Begging the question: Why couldn’t Dan be Eloise’s constant? He fed her, surely he was impt. and always there.)

Is 2004 the only time Dan traveled (seemed Des only did 1996) – you could hardly have a constant when you’re popping through time (unless you have others popping w/you, like the losties did)?

Or, is it that once you have a Constant is it ‘good’ for all time (travel)?