Who is that?

I used to be the kid who didn't really bother with studying all that much. I just did enough to get by with decent grades and that was it. I think that was how it was all the way up to pre-U. But in the past three years, I guess I must've gradually evolved with each test and each semester. Now I find myself trying to stuff in the entire contents of my very messy, long-winded and structureless marketing textbook into my head. What happened to me? Even up to a year ago, I don't think I was this nuts and I would've had more faith in my reasoning abilities. When did I become one of those people who felt compelled to memorise everything? Slap me, Jo.