what happens twice will happen three times, if it happens twice it will happen again

vicissitudes, the way that the world or a person prospers one day and declines the next

dotting the i's and crossing the t's

successive series of questions and responses

You should treasure every encounter, for it will never recur.

one part

parting, parting ways

the first in grade or rank

one case, one matter

Kyūjitai form of 一体: on earth, the heck, in the world (used for emphasis and to express incredulity)