It is not that one might forget they are armed.... but rather, having carried for so long in so many different places, one can fail to make the association between the "normal
" state of being armed, and the specific situation in which one might not be able to be armed.
Myself, living in Washingotn, I rarely go into bars/taverns, etc, but to carry in any place where one must be 21 to enter or remain, is a violation of our gun laws. Without commenting on whether that is "right", I will say that, at times, with friends who suddeny take a wild hair to go sit inside such a place, I have forgotten until already inside that I oughtn't be whilst armed. What complicates this further, our neighbour to the South, Oregon, allows carry in bars and alcohol serving food establishments (though the armed person may not consume whilst inside). Spending a fair bit of time with friends in the Portland/Vancouver area, ,some of which might enter such a place, I have to be extra vigilant to remember first, when in Washington I mayn't go in there armed, and second, when in Oregon I may, and third, to remember to remember, travelling with the same crowd, WHICH side the river I happen to find myself just then. When what is natural and normal suddenly upon a small change if cursmstances, becomes prohitbited, one can be tripped up. Thus far, I've never been caught the wrong side the line except by my own sudden awareness. Fact is, the deciding factor for me to get my Oregon Mother May I paperwork done was just that.. having driven over two hours, armed, and driving actoss that bridge into Oregon (a thing I've done perhaps a few hundred times) I suddenly realised I was, if caught, a felon...... . I discretely left the freeway and parked in an area arousing no suspicion, and disarmed myself. I learned that day the requirements, and performed the requisite obligations in acouple of weeks and received my Mother May Card two weeks on.
Now, in sharp contrast, travelling into California I NEVER forget... it is deeply impressed upon my mind that that place is DIFFERENT, and I always find a place just north of the bundary and switch to Reichmode. As soon as I pass the marker northbound, I change back into "relatively free' mode.