Humans always forget
Humans have a kind of short term memory I find it hard to describe. Within a short period they stop benefitting from someone, the are already seeking for a replacement.
More worrisome is if the cause of the withdrawal of those benefits was as a result of a misfortune, they may not bother to know how their erstwhile benefactor is doing.
You absolutely nailed it. Humans are fueled by what they can get. I got to know about them when dad passed away. I saw people for who they truly are and that gave me wisdom in dealing with people. I don't get fooled by things. I just follow my heart.
It's very good that you learnt this very valuable lesson. It would always come in handy.
Sorry to hear about your dad