It is really so tough to teach old people about bitcoin, crypto currency and block chain technology. Many people don't know about internet and features of it let alone bitcoin. But if we discuss about bitcoin with them in daily basis, then they may able to understand it.
We have to discuss bitcoin using simplified language that is easy for the layman to understand and especially for the elderly, you will go through the stages and face the challenges of making them understand about bitcoin for a long time.