older people. Tried to explain to my parents, they just don't get it. Let alone grandparents. It's a waste of time it seems.
But that's not the problem. Even regular joes just don't get it. "Where does the money come from?", "whats the intrinsic value?", and so on and so on.
What's your experience with this?
The purpose of mining is to process transactions. Since there is no centralized authority with control over the ledger (i.e. the Blockchain), there needs to be a way for transactions to be processed in a decentralized way. Miners take upon this responsibility by using their hardware to process transactions, but of course, this comes with a cost (i.e. time + cost of hardware + electrical costs). Accordingly, there needs to be an incentive for people to do this, and that's why miners are compensated with the block subsidy (currently at 25 BTC every ~10 minutes on average).
When the block subsidy runs out, there still needs to be an incentive for miners to keep processing transactions. This is where transaction fees come into play. Assuming BTC still exists when the block subsidy approaches zero, it is likely that the both the number of users and the daily volume of BTC transacted will be many times greater than what it is today, and so miners will receive the fees attached to each user transaction (by this point, it's possible that the sum of fees per block may be greater than the original 50 BTC subsidy).
"Old people" need to understand why mining is valuable and why it should be rewarded.
Don't explain it as something akin to "creating money out of thin air," but instead explain that miners are providing a useful service to the network by processing transactions, and this is a very valuable service. Because this service supports every single user of the Bitcoin economy, it makes sense that the users pay something for this service (i.e. by paying a small transaction fee). The beauty of the decentralized system is that this fee can be greatly reduced compared to other methods of payment like credit cards because the network itself only requires minimum infrastructure and therefore doesn't come with the insane overhead costs you can expect from a corporate entity like PayPal or a bank.