Recently, I've dealt with behavioral issues with my aging mother brought about by a series of different factors, but most significantly age-related cognitive decline.

Trying to determine if she was acting in a certain way intentionally or unintentionally was fundamentally impossible. In the past, I mistreated her thinking she was choosing to behave in certain ways whenever she really didn't have much of a choice, but then later I realized that to some extent and in some situations, she was. It's an extremely murky line, what decisions were being made due to other influences and what decisions were being made by her, that line never existed to begin with as who her consciousness is fundamentally is determined exclusively by 'outside' influences. Separating her identity as an entity from her material manifestation is likely nonsensical.

I'd argue that it's not obvious in it's absence, see: the philosophical zombie thought experiment

The secret is that we are all philosophical zombies to begin with.