That&#x27;s easy to answer: Dementia.<p><a href="http:&#x2F;&#x2F;www.dementiaguide.com&#x2F;symptomlibrary&#x2F;thinkingjudgement&#x2F;judgment&#x2F;" rel="nofollow">http:&#x2F;&#x2F;www.dementiaguide.com&#x2F;symptomlibrary&#x2F;thinkingjudgemen...</a><p>Dementia can grow slowly over time and can impact your judgement. And said person can be highly functional at the time, so the relatives don&#x27;t know until something goes wrong.