I disagree.  There's no need to explain cryptography and blockchains to people, but they will have some preconceptions from Paypal.  You need to explain these things or they'll end up angry and never want to touch Bitcoins again:

• There are no chargebacks.
• If you lose your wallet or password, it's gone forever.
• The value (and therefore the price of goods) fluctuates much faster than most fiat.

By the time you've explained those things, they'll be wondering why you think this is a good idea, so you need to keep explaining:

• Unlike PPUSD, your BTC are truly yours, and can't be "frozen" by some surly bureaucrat
• You can spend them freely - across borders, to unpopular causes
• Anyone can use it without signing a huge contract
• The fees are extremely small

... But that's a heck of a lot to explain just to send someone a little money to play with.