Later Sunday: write another entry (and more numbers) in my checkbook. Mistake the "4" for a "1," and subtract accordingly.
Today: look at online banking to reconcile amounts, and think "What did I spend $30 on?" then think "Oh, I didn't."
Couldn't I have written the 4-not-1 one column to the left, so it'd be $300 I didn't know I had? Or one column to the left more, so it'd be $3000? I can dream can't I.