if people want to make their investment in bitcoin, they should learn and know why they choose bitcoin for the investment, and they need to have method or strategy how they used bitcoin as the investment. Besides that, they need to have a strong control for themselves, so they don't panic if the market is decreasing like today.
My take on most people that wants to invest is that they really need to learn and understand what investment is all about, and need to understand the difference between short term investment and long term investment, because I have seen that what usually make people panic sometimes is lack of patience, and the reason for this is that they tie the investment that is meant to be a long term investment to a short term investment, and when they do so, they become too agitated every time they monitor the rice of bitcoin, and investment is something they are meant to leave there for a long period of time while facing other things in the market, and checking on such investment should be periodically and not like every hour that people check on their investment.
Bitcoin is not ready to be used as a currency yet, that comes later.
What you mean by "ready". Already
lots of merchants started accepting bitcoins as one of payment options. Bitcoin is already a currency but not available for every part of people yet.