This goal is pretty high to have 21 bitcoin. I don' t think I will reach that.
The reason for that is because I don't think I put enough money into bitcoin to be able to reach that and freelance jobs don't pay that good just a few. So probably I will hover around 15 before it reaches 1k cause I'm almost there already. But there's no super rush can still earn them when they are a little bit more expensive aswell.
It doesn't really matter whether or not you'll reach 21BTC as that many coins is not a realistic target for the majority of the people. That's why you should be happy with the coins that you have right now. And if Bitcoin lives up to what is (realistically) expected and its potential, then you'll see that even a lower number of coins can also give you amazing returns.