The question shouldn’t be fate or not fate.. We sometimes know the reasons behind some incidents, other times the reasons remain hidden. It’s not our duty to look for them either, as it would open an endless ocean of misery. What we should be interested in is our duty. Were we good enough? Did we do our best? If the answer is yes, then we don’t and never have to worry about anything in our lives, since it is all moving upon Allah’s will.