It is not just your imagination—your tea really does taste better from your favorite cup.
The psychologist quoted in the linked-to article says that "Caffeine is very much a drug of reward and like any addict, people develop passions on how the drug is delivered."
Yikes. That makes we green tea drinkers sound like a bunch of junkies. Instead, I think that the relaxing ritual of preparing green tea really does make your tea taste better. That is because the ritual relaxes us, allowing us to focus on the flavor and appreciate it more.
The psychologist is right about one thing, however: Green tea is a great way to reward yourself.
That cup may not be your cup of tea, but to each his own, yes?