What essential things should everyone understand about Bitcoin?

There literally so many point. Everyone (who is curious about Bitcoin) knows about the limited circulation, and that its Internet money, and its market cap is so and so, here are some pragmatic points for the world on the whole:

• First and foremost it is a protocol
• The first app developed for this protocol happens to be money, the Bitcoin money!
• Transactions are irreversible
• The ledger is open for all to see (with regards to a transfer between wallets)
• Despite the ho-hah, many people don't know how to Buy bitcoins!
• For international users (read: outside the US, Canada, UK, etc.) the process to buy Bitcoins from an exchange can take between 5-10 days (to get verified and for funds to be realized)
• The best way to get bitcoins is to sell a product and/or a service and receive the payment in Bitcoins
• Despite the progress made by companies such as Bitpay and Coinbase, accepting Bitcoins (for merchant) without the volatility in its price, is not available to the most of the developing world (very few countries are covered)
• The transaction is almost instantaneous, 10 minutes for a transaction to be confirmed.
• The transfer itself has no bearing on the value, you can transfer US$ 1 or US$ 100 Million, Bitcoin makes it seamless. Only the exchanges and transfers onto other currencies is where the fees are applicable. In some cases online wallet companies may also impose a fees.
• The process of owning, trading, buying/selling bitcoins is still a little complicated for the general public use.
• Bitcoins are stored in wallets. If your wallet is compromised, your money is gone. Period.
• No one controls it. (despite this being covered in so many articles, people keep asking, well someone has to control it).

A post I did on Bitcoins recently is worth a read: Bitcoins: Everything you wanted to know about Bitcoins, but were afraid to ask!