Whenever I’m critiqued at work, I generally take it on the chin and don’t offer excuses. That being said, if I had good reason to do whatever I did, or I think it would help to explain my thought process, I try to do so in the interest of working with my superior to help me better understand where I went wrong and/or how to course correct in the future. However, when I try to explain myself, I’m accused of “making excuses” and am told to “just take it and say thank you.” (Cont. in comments)

I hate when people have a negative reaction to an explanation of why you did what you did. Those people are idiots and would be angry if someone reacted that way to their attempts to explain.

Unless you are responding in a way that is combative, a superior shouldn’t be bothered by hearing your thought process; they should listen and help you determine where you went wrong.

The best advice I’ve heard for giving feedback is to offer advice, not criticisms. It comes across as less harsh and typically the advice-giver will couch the critique with actionable feedback. Can you kind of reverse that, and approach it as seeking advice on how to do better next time? Maybe “thank you for the feedback. I want to do the best job possible. How would you recommend I address X?”

I agree that this issue is super tough. You want people to understand that it wasn’t a typo or a mistake.

The best I’ve figured out to do is to ask a follow up question and include an explanation of my thought process in that follow up question. So, say something like, “I wanted to follow up with you about XYZ. I was initially thinking, blah blah blah, but I saw your note saying blah blah blah…”

I genuinely am not trying to make excuses for the sake of it - but my bosses think that “excuses” and “explanations” are the same thing and I shouldn’t stand up for myself where I think I need to or explain my reasoning in order to understand where I went wrong. Should I really just be saying “I’m sorry, thanks” each time I get feedback, even if I had a genuinely valid reason for doing whatever I did and I want my bosses to know there was thought behind my choice so we can course-correct?

It's probably more in how you are offering your insight rather than what you're saying. Many people, when critiqued, immediately fire off a defensive answer for why they did what they did, but sometimes 1) why you did it doesn't matter, so the supervisor doesn't want to waste time hearing the explanation, 2) the explanation comes off so defensive that the supervisor feels it would be pointless to continue going back and forth countering the explanation.
If you come at the feedback with questions more than statements it might help. (Ex: "what if I was trying to defend against personal jurisdiction rather than XYZ?" Might come off nicer than, "well I was trying to do XYZ instead.") Maybe the questions will even make them start thinking more.

My advice assumes you’re talking about differences in approach/opinion, not actual mistakes that you’re making:

If you start out your response with, “Thanks, I’ll make that change.” it will calm your recipient and make them feel heard from the outset. Now they’re in a better frame of mind heading into your next sentence, which can either be a request for clarification, a gentle pushback (“for whatever it’s worth, my thoughts in approaching this way were ______; I’d be interested in hearing your take on that”), or what have you. You’re showing the deference they clearly want while also saying your piece (and you may have a good point they didn’t think of). Don’t apologize. Be respectful and let them feel heard, and then take up your own space in the conversation.

I’m just scared of never explaining myself and allowing people to assume whatever they want about my capabilities/intelligence and eventually getting frozen out because of a disconnect. I want to be able to advocate for myself at work, but if I’m taking the wrong tack or it’s inappropriate to do so, I’d rather know.

Anyone who responds with “just take it” is gross and you should find a way to leave.

Like…take it like a punishment? It’s ridiculous and unprofessional of them. If they think you’re being too defensive they can address it in a reasonable way.