celticdragonfly

When I use that phrase it usually means, "I'm doing X, and I know it might affect you negatively, but my reasons for doing X don't actually have very much to do with you at all." For example, I ask people not to take it personally when I cannot attend parties on a Sunday because I teach all day, or when I can't stay out late on a Saturday night for the same reason. I'm not telling them that they shouldn't feel disappointed, but that there are pre-existing conditions or committments in my life that take precedence over my wish to attend their birthday party. I'm not in a position to put my livelihood at risk like that, even if it is at odd hours compared to when they earn their living. Yes, I have had people get offended about this; they took it very personally that I wasn't willing to cancel a week's work in order to spend time with them.

I suspect this is not the same context as the one you meant.

I want to find strategies and answers so I can never let that phrase get used on me again.

I don't think people always mean "You shouldn't have feelings..." when they say, "Please, don't take this personally, but...", although I agree that they often may be asking that.

I don't think there is a way to stop other people saying something to you. You might be able to get to a point where you can set some sort of boundary with how much you are willing to let your own feelings be influenced by what someone else wants you to feel, though, and then you might not feel so defensive? I'm not sure.