Er, is overleveling ever bad?

Sometimes I overlevel because I do this weird thing where I'll read a book and play a videogame at the same time. And most RPGs have kind of mindless battle systems, sadly, so I just circle the dungeon and just press X repeatedly, read my book, pay attention to some plot, read my book.

I don't do it all the time, I swear. But when I do, it results in pretty high levels in some games that have leveling that works that way.