Rookie Mistakes.. (I've made a couple whoppers so far)

Soooo I decided to hit Jewel last.. I needed Milk really bad and it was free after buying 5 boxes of GM cereal for $10. Of course I had plenty of coupons so my total would have been $6.50 for 5 boxes of cereal. I also had a catalina for v8 fusion $1.25 and had found another $1 coupon for that. I saw gronola bars on sale for $2.50a box and remembered I had $1 coupon tucked in my coupon book.. took that out. So my total after all sales and coupons was $9.52.. trusty CATALINA prints out the coupon for the free milk. I had put the milk behind the ceral boxes so I could do that as a separate transaction.. Dumb butttttyyy me never clued in the fact that the catalina freebie could possibly print for more than the actual cost of the milk and didn't include a filler in order #2. So of course little pimple face Johnny rings it up and tells me I owe 64 cents when it was showing as a NEGATIVE, so he gets all freaked out and calls everybody and their mother manager over.. so they void the coupon and just give me the price of the item which was $3.79 and I had to pay tax! duh!! oh well.. so I paid $9.59 for basically $30 worth of groceries.. not too bad.

#2 as I walked out of Jewel I saw a huge garbage bin filled with CATALINAS.. of course there was this lady right on my butt so I didn't stop and try to grab them.. ughh!!