What just happened here? (Walgreens)

Well, I just got back from my Walgreens trip and I'm scratching my head because I spent way more than projected. Here's the breakdown:

2 Powerade @ 1.19 each - .30 x 2 (in-ad coupon for .89) - 1.00 coupon x 2 = .22 overage

2 Loreal Vive Shampoo and Conditioner 4.99 each - BOGO from store - BOGO coupon = FREE

(not on projected list ) 2 Smart Rinse mouthwash on clearance for 1.99 - 1.00 coupon = 2.98

Rightguard Extreme on sale for 3.99 - $2 mail-in rebate (forgot about that; just went and saved my receipt online) - 1.00 coupon = .99 (2.99 right now)

2 Fusion Aftershave gels that were on the clearance rack. Hubby mentioned needing some and I don't currently have any coupons/deals = 1.49 x 2 = 3.48

Raid twin-pack 6.99 - $1 IVC coupon - Hummmm I don't see my other $1 MFC scanned. Wonder how that happened... = 5.99 Grrr should be 4.99

Nursing pads 4.99 - 2 IVC coupon = 2.99 This was not on my projected list, but I discovered that I needed some and this was the best deal this week

2 Robitussin cough drop bags on clearance for .49 each = .98

2 Schick Quattro razors @ 5.99 - BOGO coupon - $2 IVC x 2 = 1.99

Total=21.18 - $2 rebate = 19.18

10.43 of unprojected purchases

Now, I could spend a lot of time justifying how I needed this or that, but that fact remains that I really had no idea when I went up to the register oh how much money I was going to spend and thus, I stood there and stared at my receipt wondering why it was $24 (w/tax) and not $9. No, I did not take a calculator with me (though I can easily use my cell phone), no I didn't stick to my list, no I didn't take cash only, and no, I didn't pay attention. All of these things are budget busters.

So, here is my goal for next time:

To better plan and account for EVERYTHING that I am going to buy when I go. I had it in the back of my head that I would look at all the things that I highlighted in red, but I forgot to account for it in my total to spend. So, next time I will go knowing that if I am going to look at aftershave because Jim wants some, purchasing the item will increase my bill by X, or I will need to take out something else that I had planned to buy.

So, that's my learning trip for this week. Will I ever learn???

***Note: a commenter asked if you can use an in-ad coupon stacked with an IVC coupon. The answer is: YES!!!