졸리다 is the feeling of being sleepy, not the act of sleeping. Five of these lines are the same complaint — 왜 이렇게 졸리지, 'why am I so sleepy?' — usually said aloud to nobody in particular, with 춘곤증 'spring drowsiness' offered as the reason in one. Keep it apart from 자다 'to sleep' and 잠들다 'to fall asleep', neither of which describes the feeling.