It's Valentine's Day, the preordained time of year to demonstrate that you're the romantic maestro who knows your partner better than you know yourself—because delivering a romantic gift requires understanding your relationship. If you've been married for a long time, you undoubtedly (or should) know them very well; nonetheless, it may be difficult to surprise them with yet another gift year after year. Your better half, on the other hand, is well-versed in your routine. And if you've just been dating for three months, you still have a lot to learn, such as what kind of present will hit the...