No one I know understands it properly. Some of my friends do, but they no longer use it haha.
Really true that many of my friends who knows about Bitcoins but don't trust it completely and due the jobs timings some of them they are busy and take rest in the evening. And its true that many of them doesn't understand and they even don't try it. Because they don't know how fruitful is Bitcoins.
The key is being able to inform them of the value of BTC and what the future could be. Bitcoin is like a stock right now and the only way it can go is up, if people continue to use it and increase their spending in BTC. The more people that use it, the better the value, because it will be more in demand. Give the people what they want, but you need to show them what they are supposed to want!