Reminds me of various old rpg games, where the more skills/perks/traits you started with and the more your lvlup gains got boosted,the slower you gained levels.
(Not too rare with those you could choose to have every single bonus possible at start, but lvling got ridiculously slow at that point, like reaching lvl 3 when others reached 20+.)
Remember, he got a ridiculous amount of skills/perks/traits, even if most on their own aint all that great. (And wouldn't surprise me if author played one of those games.)