no need to be sure about bitcoin as you cant predicted the future. bitcoin as we see his history are very positive. it crash it rises again. how many times people like you said i will death but bitcoin still steady till this day. so im think this was not a stupid move at all to hold tight bitcoin.
Some people don't know the price list. That the reason of more loss. So before invest check the coin price list then invest. If price will be low buy and hold long time. Bitcoin price is any time to increase the price. So that time sell it. So time is important of this investment. Every day follow the market price list. Then get ideas for buy and sell on time. Then easy to complete the process.