Focus on sudden or unpredicted changes; not all changes are vicissitudes. After winning the lottery, his life took a vicissitude that surprised everyone.
Pro Tip 2/3
Neutral Tone
Although often negative, 'vicissitude' can describe neutral or positive changes. The vicissitude of seasons brings new challenges and joys each year.
Pro Tip 3/3
Emphasize Impact
Use 'vicissitude' for changes that impact one's life significantly, not trivial matters. His career's vicissitudes made him reconsider his goals.