Hello there! Let's talk about how bitcoin will become the national currency of each country (if you want so, of course). Bitcoin is a virtual currency who's popularity increased exponential in the past years, and I think it will become even much more.
First of all, let me tell you how bitcoin works (if you do already know, just skip this paragraph). I want to tell you what makes it capable of becoming something greater than normal currency. Bitcoin uses block chain, which is nothing more than a list of transactions. There, you can find the transaction of every bit of bitcoin. So, you actually posses the end of a long chain of transaction (this is what you have by buying bitcoin). You can then continue the chain, and lose the bitcoin (which is a transaction) in exchange of other things (like food, services or anything you can buy with normal money).
Let's say that the government will use bitcoin for everyday transactions, and it will have all the mining power (because the algorithm won't be public). Now, every citizen will pay using the country's bitcoin, and the country will take commissions from those transactions. But, here comes the fun part. As the addresses for government will be public, you will see where your commission went. Moreover, you will also see where those money goes afterwards. That means...exactly, no more overpaying done by the government, no more stealing and no more corruption. There could be done laws using the addresses of your wallets, and having more than one would be illegal, so you can see if a big transactions happens, and it will be known the persons who done it and they will be interrogated.
All in all, I am sure that bitcoin will increase more and more over time, and the best time to buy it is now :)