Do you ever carelessly say "gonna" instead of "going to"? That's the way language has been changing and making new words for millennia. The Indo-European root words for "go" and "carry" (words that sounded something like "bear" and "ink") ran together to become the English word "bring". There also used to be a word that meant "repeatedly" that's now just the suffix "le" in English; it's the difference between dab and dabble, drip and dribble.
I learned this from The Story of Human Language, a Teaching Company course on CD which is a series of lectures by linguist John McWhorter. The Berkeley Heights Public Library has over 200 courses, on CD, DVD and audiocassette tapes by the Teaching Company and Recorded Book's Modern Scholar.
If linguistics isn't that interesting to you, there are science, religion, history, philosophy, art and music courses to choose from, like How to Listen To and Understand Opera (which is what my mom's listening to). You'll feel like you're in college again!