Tea can be temperamental and need some warming up before it will brew a really solid cup. You may have found that if your pot is too hot or if the water temperature isn't just right, your ideal cup of tea doesn't turn out quite the way you may have expected it to.
Tea also seems to get jet lag sometimes. It may be the high air pressure, the cold of the cargo hold. . . which leads tea to taste bland, lifeless or just plain bad after it travels. Like people, tea may need to rest for a bit after its flight. A sealed bag of oolong needs to be opened up to breathe before it completely comes back go life. Transferring it from the bag into a jar will do wonders for it. Give it a week or two and try it again, it will taste different and open up for you to enjoy.
I've been relatively critical when tea tasting in the past. When one is on a mission to buy teas, there isn't much time to explore each one in depth. Decisions are made on the spot and tea buyers do their best to guess the potential of the tea and how it will change over a given season. When tasting tea with friends, I have also been quite critical of brews that lack the bouquet, the essence or the range of expected tea traits.
The longer I drink tea, the less judgmental I become. Maybe this naturally comes with aging and maturity! I know what I like and want, but I’m also accepting of all sorts of brews and I trust that many teas have more to share than what I may have experienced with them. Nowadays, I can only say what my initial thoughts are about a tea, I’m not usually inclined to judge how terrible it may be – although there are certain brews that seem so bad that one can never imagine them improving.
I’m especially silent when it comes to predicting how a pu'er will turn out. I have read and been told about so many different ways for judging how worthy a particular cake may be for aging. Aside from fundamentals such as using good raw materials, correct pressing procedures, proper blending, etc, I have yet to meet anyone that can definitively and accurately predict just how good a particular cake will become decades after it was pressed. Do the best ones start off smoky? Rich? Sweet? Woody and camphor-like? My oldest raw teas surpass 50 years and they are still changing. My mid 2000s brand-name old arbor cake started off grassy and smoky, then became a bit flat, and is now somewhat sweet and mellow.
What's next? Actually, not knowing for sure is part of the fun.