Aging Wines

[iman]

Hi, i've been drinking wine for some time, and the idea of saving a full bottle of wine to have years from now has always appealed to me. However someone told me that I needed favorable conditions in order for the wine not to go bad, and that not all wines can be aged. Is that true? Do the wines I'd buy in a liquor store have addictives added to them, so they don't loose taste?