Depends what you mean by fine. I am certain everything won't be fine if we stay in.
Completely agree there is no precedent which makes all the definitive forecasts pro or anti Brexit pure guesswork.
You can keep telling yourself that but the studies by every single reputable organisation under the sun that say that we will be poorer, significantly poorer, post-Brexit didn't get their figures out of thin air. Please heed the warnings of the IMF, OECD and Treasury - recession + job losses + years of uncertainty.