How do I explain my failed career decision to a potential postdoctoral/academic manager/employer, when I'm almost seven years past my PhD?
I think the answer you have now isn't so bad. But you could be painting yourself in better light. Rather than saying jobs in academia in the pay range and stability you aspired to were too competitive, say you preferred the higher pay and stability you could access in industry. It's the same sentiment but doesn't point to you somehow failing. Many good people get bad luck and don't make it to tenure, and we all know industry offers a wider range of people a better material life in many aspects.
So for example I would tweak this to:
&quot;Initially I wanted to move into industry for (better reasons to reference: higher pay and a more stable lifestyle, choosing where you get to live, etc). So I moved to industry. In R&amp;D and I thought I'd be doing almost fundamental research; but I was wrong - the industry mindset and environment I found to be very different than the academic one, and hence I'm realizing my mistake only now, and trace my way back into academia.&quot;
And then maybe say that you've realized it's important to you to be doing fundamental research, so important that the pros of getting back on the academic track now outweigh the cons for you.
Caveat: I'm not in mathematics but in my field your publication record doesn't justify looking for a permanent position, and that would be immediately known to people interviewing you for a postdoc. They may instead phrase this question more like &quot;what have you been up to?&quot; Or maybe even directly ask, &quot;why did you leave industry?&quot;