Simpson, married to his childhood sweetheart for almost 19 years, had walked out on his wife and kids and into the arms of a younger woman. The breakup surprised his wife, his friends and even Simpson himself. Looking back, he says, it was a classic midlife crisis.
In that we have already provided the definitive answer to this question elsewhere (relying on rum extract), we assume your follow-up is seeking a non-alcoholic substitute for rum (as extracts can be as alcoholic as or more alcoholic than the spirits they replace).
Vodka has the most neutral flavor, but you can also use bourbon, brandy, or rum to create unique extracts. There's no need to use a top-shelf or high-proof alcohol when making vanilla extract. An inexpensive 40% (80 proof) alcohol will work just fine. (Commercial vanilla extracts are typically 35% or 70 proof alcohol.) I prefer using a mid-tier alcohol, not bottom of the barrel but not too expensive, either.