If you haven’t done the first part of the HoT storyline and unlocked masteries then the XP is lost.
What Wethospu is referring to is what happens after you’ve unlocked masteries and maxed one of the tracks. Once you’ve got enough XP you have to manually spend the mastery points to activate the track and move on to the next one. If you don’t remember to do that (or if you get more than enough XP when you finish it) any XP you earn will go into another track.
Fortunately because most of the content in this game is repeatable and almost everything gives you XP it’s not a big deal if you do lose some. The HoT launch seemed very relaxed to me after watching people reacting to a new use for XP in my other MMO (where most XP comes from non-repeatable quests) there were huge discussions and debates about the best ways to ‘save up’ XP, and people stopping playing completely so they didn’t accidentally waste XP because it would be so hard to make up the difference if they did.
Danielle Aurorel, Dear Dragon We Got Your Cookies [Nom], Desolation (EU).
“Life’s a journey, not a destination.”
