The difference between lie and lay

Man oh man. Shit tons of reading being done. Beginning to worry if my eyes can handle it. No long forming complete sentences. Picked up Desert by J. M. G. Le Clezio, and so far it's pretty good. Been keeping a solid rate of about 1,200 words per day. More excited every day about the move to California. Less excited every day about breathing kids' farts and selling toys. I guess this is what I've heard-tell is "optimism." I hope that doesn't mean I need glasses.