My style is basically grunge rocker girl: ancient jeans, a vintage rock T-shirt, and bedhead. I need photos of myself, so late Saturday afternoon, I did a photo shoot with a professional stylist, makeup artist, and photographer. Long story short, I despise all the photos. They dressed me in "nice lady" clothes I hated and put too much makeup on me, including lipstick, which I never wear. I'm normally pretty assertive, so I don't understand why I didn't speak up for myself.

--Irritated

When your style is grunge femme -- bedhead and jeans that appear to be loaners from a wino -- it's a major bummer to pay for photos that make you look like you sell high-end real estate via bus bench ads.

It's especially bummerific when you could have spoken up but instead just went along like a lap dog in a bee outfit. But the reality is, your ability to assert yourself -- which comes out of a set of cognitive processes called "executive functions" -- can get a little beaten down.

Executive functions are basically the COO (chief operating officer) of you -- the cerebral department of getting stuff done, through, among other things, planning, prioritizing, holding sets of facts in mind, and making choices. And then there's the executive function that crapped out on you: "inhibitory control," which, as cognitive neuroscientist Adele Diamond explains, allows you to direct your "attention, behavior, thoughts, and/or emotions." This, in turn, empowers you to do what you know you should -- like eating your green beans instead of going with what your impulses are suggesting: faceplanting in a plate of fries and soldiering on to do the same in a bowl of chocolate frosting.

As I explain in my "science-help" book, "Unf*ckology: A Field Guide to Living with Guts and Confidence," our mental energy to keep our executive functions powered up gets eroded by stress, fatigue, hunger, and even seemingly minor mental chores -- like choosing between the 30 slightly different kinds of balsamic at the supermarket. Basically, as the day draws on and you put weight on your executive functions, you wear out their ability to be there for you.

So, what can you do to avoid repeating this experience? Try to schedule tiring, emotionally taxing projects earlier in the day. It also helps to figure out ahead of time where your boundaries lie -- stylistic or otherwise. Then, when somebody does something you're not comfortable with, you've pre-identified it as a no-no, which makes it easier for you to stand up for yourself -- calmly and firmly. Remember, "every picture tells a story" -- and it's best if yours doesn't seem to be about the time the lady at the Estee Lauder counter held you down, made you up, and then pulled out her Ruger and forced you into mom jeans.

For pages and pages of "science-help" from me, buy my latest book, "Unf*ckology: A Field Guide to Living with Guts and Confidence." It lays out the PROCESS of transforming to live w/confidence.