If you are searching for alternative words or expressions for "hadst occasion to," there are many options available. Instead of using this old-fashioned phrasing, you could say "had the opportunity to," "experienced," "encountered," "presented with," or "faced with." These synonyms can be used interchangeably depending on the context of your sentence. For example, "had the opportunity to" can be used when discussing being granted an advantageous position, while "experienced" is useful when documenting personal trials or past successes. Each of these variations helps you to communicate more effectively and avoid sounding outdated or old-fashioned.