adjective

Happening or carried on according to chance rather than design or inherent nature.

my adventures were always adventitious, always thrust on me

unplanned,unpremeditated,accidental,unintentional,unintended,unexpected,unforeseen,involuntary,chance,fortuitous,serendipitous,coincidental,casual,random,fluky,unlooked-for,unhoped-for,not bargained for,out of the blue,without warning