because bitcoin prices can sometimes rise as high as the sky and sometimes fall deeply, bitcoin is unpredictable and makes the heart rate increase when investing.
The current price may not be that good, but I'm sure it will get better by the end of 2018.
Bitcoin makes the world go crazy because it puts people from surprise to surprise. It can cause your property to multiply and also fall in price the next day. Its potential is likely to also cause this madness. It shows the possibilities and limits that humans can achieve in the future.