No. Nobody does.
Actually, it depends if you your estimation. If you expect on 1-2-3 years, your expectataions are may be not wrong, but better expect growth in 20-30 years. If you think this way, invest, and your patience will be rewarded. My own opinion, i don't pretend to be thruthful.
Well, you can ask 10 different experts for how long you should hold your BTC, and they will give you 10 different answers. You need to reach on a figure, depending on the risk taking ability and the share of cryptocurrency in your portfolio. But personally, I think that holding these coins for 30 years is not very practical. Although Bitcoin is without any serious competition right now, it will be foolish to assume that the status quo will continue in the near future. After all, Bitcoin is a technological asset. New innovations frequently make the older ones obsolete, and at some point of time the same is going to happen with Bitcoin as well.