I first realized it the day my father asked me which number came between 3 and 5.
He had been living alone for a while in another state and I only saw him a few times a year, but while speaking to him on the phone it became more evident after he would repeatedly ask how to write a check and no longer knew where the grocery store was located. Months past and it was clear that he was not safe living alone. He was not able to manage daily situations, such as an ATM, finding milk in a store, or remembering where he was.