I really wish that it would progress past 3 months (like if you get it right at 3 months then it goes to 4 months, 5 months, 6 months and so on). Once it's really firmly planted in your long-term memory you shouldn't need to water it so often.
I, for one, welcome our new plant overlords. I would practice more if my garden featured plant-zilla creatures.
@ marygavin - Nothing happens as far as I know (though there's been discussions about building in rewards and badges etc for these sort of milestones, so that will probably happen in the future). There's no cut off point - you can just keep on learning and learning.
I wonder if they ever incorporate such things as "achievements", will you get them subsequently? Things like "1000 words - Here's your Golden Watering Can(TM)" or "Watered more than 20 words each day for more than 2 weeks - Garden Hose Extension 2000(TM) awarded!" would be pretty funny ___