gradual versus sudden enlightenment

Is it true that most "enlightened" Buddhists attained this realization gradually? Or are there cases of sudden enlightenment? I ask because either this process is way more gradual than I can even detect, or else I'm not yet at the sudden point. Or perhaps I won't ever get to that point at all. I'm pretty new to all this - been meditating daily for about a year now, at first once a day for 20 minutes, then 30 minutes, and lately twice a day for 20 minutes each...I feel so clueless. And my mind continue to race all over the place when I'm sitting. :-)