Being optimistic 101. Find possible positive things in all situation. I assume that this market dip is just a hard reset of the market's value where 'virus' or unworthy investors, mostly those who panic sell, forced to withdraw their account because of the dip. With this, all weak accounts will be perished and all remaining strong holders go on to victory. After it has been cleaned, we could now enjoy green fields on our wallet. 2019 will be great again for us crypto holders. Stay focused.
It's really not about being optimistic. It's about being rational.
We know that we are in a period of a market reset, and that has happened basically throughout every single asset that is traded on the free market, and since the existence of bitcoin. Bear markets aren't anything abnormal and doesn't suggest anything fundamentally wrong about bitcoin.
All it is is a necessary correction from an overheated bull market of 2017, leading to prices dipping and market activity faltering. If you invest in bitcoin in the long run, or as a hedge against fiat, you shouldn't be panicking. Even though I don't expect 2019 to be the year a bull market emerges, I do think that it is a matter of time before prices recover, since bitcoin adoption especially on an institutional scale as increased despite this bear market.