Each common skill may be acquired every 10 levels based on the individual character level. For example, if the character level is 40, each skill can be mastered up to level 4. However, the Expand Trade skill mastery levels are as follows: Level 40 (level 1), Level 55 (level 2), Level 65 (level 3).
If the difference between the character level and the skill level becomes greater than 10 levels for a previously learned skill, the acquired skill will automatically disappear.
This is in the C4 feature list in Skills and Magic, can someone clairify what the red sentance means? I just got expand inventory lvl 1 at lvl 52, does that mean i loose it at lvl 63 if i dont upgade it to expand inventory lvl 2?