From Lama Yeshe and Jack Kornfield with a bit of editing from me: If [we] expect [our] life to be up and down, [our] mind will be much more peaceful. Peace is born out of equanimity [upekshanam in Sanskrit - see Patanjali I.33] and balance. Balance [which requires inner strength] is flexibility, an ability to adjust graciously to change. Equanimity arises when [we begin by] accept[ing] the way things are....
Happy exploring!