If you mastered Cyber Monday and saved hundreds of dollars, I am so impressed with you! Here's how I failed.

Usually I'm a pretty frugal shopper, and know which coupons can be combined with percent-off sales, and I trust my gut on an average weekend when it tells me to skip the 15-percent off sale because 25 has to be right around the corner.

But Cyber Monday is a whole different animal! It's like Las Vegas, and I've been spending my time on casino boats in Shreveport. I'm not good at Cyber Monday.

My nieces said they want Under Armour shirts and sweatshirts for Christmas, and I thought that would be pretty easy to pull off without spending too much. I got an email from a sporting goods store Sunday night about a 30-percent off entire purchase sale on Cyber Monday, so I totally thought I was going to score.

The percentage off would decrease to 25 after 6 a.m. Eastern time, but I was us up early and knew I could save the 30. Until I screwed up the time zone and noticed at the top of my screen the 30-percent disappeared and morphed into 25.

Dang it! Time zone fail. I needed more coffee.

With two Under Armour sweatshirts and two Under Armour long-sleeved shirts in my cart I decided to check out right then, and save the 25 percent instead of 30, and get over what turned out to be about a $7 difference. I could skip a latte this week and make that up.

But there was another fail waiting for me, and maybe you wise shoppers can already see it coming. When I tried to apply the coupon code to get the 25 percent off, it told me the Under Armour brand was one of the brands that was excluded from the promotion.

Dang it! Don't you hate that?! Some brands never let us use coupons and they're never part of sales, and we love them anyway and gobble up their stuff like it's an oasis of chocolate an we can't believe we get to have some.

How do they do that?

So I paid full price for the sweatshirts and shirts, and I hope my nieces love them. And I really hope they're not reading this blog right now. In that case, I guess there's no point in taking the price tag off before I wrap it, huh girls?

I quit Cyber Monday after this, and left hundreds of dollars in savings on the table I'm sure. Oh well.

Any Cyber Monday successes or fails for you? Twenty-four shopping days left until Christmas. Good luck with that!