Just kidding, wine does expire but it depends on the quality of the wine you purchased. Good quality wines can be stored even for a hundred years and still be drinkable. Poor bottling or microbial contamination can ruin even the best wines.
So what do you look for:
Scent: if it smells like a barnyard, sweaty horse, band-aids or manure it can be caused by bacteria. After the wine hits oxygen it will begin to get a strong vinegar scent.
Taste: lactic acid gone wild will make it taste like sauerkaut.
There are a ton of problems that can happen and La Crema offers the below