Making old people understand Bitcoin isn't an easy thing to do. Don't expect them to get everything after telling them about it for two hours. These old people are smart about money and telling them the advantages of buying a bitcoin or trying to mine bitcoin isn't gonna get them there. It's going to be easier if a person someone close to them is going to introduce it and of course that person should show results that they're earning from it. If other people introduced my mom to cryptocurrency, they wouldn't have believed it. But because of the results my brother was able to produce, it became easier.