I worked with my son on a mining rig (computer), when I started to explain what a Bitcoin is.
Why would someone want to use Bitcoins instead of cash?
But doesn’t this mean, that all banks will go bancrupt?
Why would someone use BitCoin instead of PayPal, which is a working and existing system?
What happens if my computer breaks? [store your cash in your house – loose everything][backups are crucial – examples]
Who is in control? Who will work in a worst case scenario?
Examples: Game for swizzerland + humble bundle transactions
Other pages that explains it easily: