The idea of investing no more than you can afford to lose is the same as making sure that you are investing within your discretionary income and not using money that you need for expenses. Also bitcoin is not guaranteed to be successful, so everyone should realize that he could lose up to 100% of what he puts into bitcoin. Surely no one invests into bitcoin (or anything else) or even engages in trading with any intention to lose, yet they still need to account for the possibility that they are not using money that they need for their expenses whether expenses in the coming month or two or even expenses down the road.
That’s true eventually as, the idea of how Bitcoin investments should be approached and I agree on the not having a 100% guarantee on it but, it has some guarantee none the less, especially when compared with the many altcoins out there. Bitcoin has more proven guarantee then the lots of them, deeply rooted in its price history and how it’s carried despite many critic and attacks.