Mastery Rank
It’s just ppl with hardcore time investment – they spend huge amounts of time in game, but also quickly discover optimum xp farming areas, with xp boosters going at all times.
It’s about time and efficiency. Not something that I could do, but it is how some like to play. It’s not you doing anything wrong.
The rank is the amount of points spent. The higher ranks cost more points. You could level 1 mastery track 4 times and be rank 20, or level 4 different masteries and be rank 5.
The displayed rank is misleading.
That person farmed the CoF p1 dungeon to max out hes core tyria masteries. He only went up 3 ranks because he leveled one of the maguuma masteries to its level 2 state (costing 3 points)
Your playing the way anet intended (IMO) and your doing just fine. from the advise we give to the new players, take your time and enjoy the content. You will only get one chance at experiencing the game that way as as soon as your masteries are unlocked it will become different