You are right. There will be some seriously bad months for reasons that we never foresaw. I am an optimistic person. It does seem inconceivable that bitcoin could reach these lofty highs, yet the maths says it will. Go back in time and you will find other projections which were regarded as over optimistic or wrong but came true.
"There’s no chance that the iPhone is going to get any significant market share.” — Steve Ballmer, Microsoft CEO