An old Zen story teaches that when an intelligent person requests knowledge from a Zen master, he must empty his cup before he can taste the master's cup of tea (knowledge). I like these tea cup stories! Here's my Tibetan Buddhist expansion on the old Zen story of the "too full cup".
There seems to be more to the tea story - there are levels and levels to some things, eh? And, those on one level may not see or know of the existence of others! Actually when anyone (intelligent or experienced or otherwise) requests knowledge from a master they must empty the cup - but there is more to the situation than just the cup! There are many different properties of: cups; tea; tea pots; and, those offering them.
The cup may be already full (incapable of taking more or different tea); partially full (resulting in mixed, impure tea - some stale, some fresh); upside down (in the wrong postion to receive tea); have a hole (not being able to contain what it is given - a worthless cup); held above the teapot spout (in the wrong attitude to recieve tea); tainted with dirt (tainting the tea it receives, changing its nature); and, then there is the cup that spills (wasting the tea, perhaps burning others).
The tea may be stale; imported; stolen; bitter; re-packaged; over-priced; free; pure; mixed with other foreign non-tea ingredients; soporific; hallucinogenic; of high or low quality; too little, too much; a lot - or just plain tea. Is one cup enough? How much do you need to drink? What are the consequences of drinking much of each of these types of tea? Should one mix teas? The person offering may offer the cup to incur obligation; to enlist another follower to increase his fame and/or fortune; to poison; without any intent or genuine interest other than common courtesy; or, in all sincerity. He may be a master or a semblance of one - a master even in other traditions perhaps - or an actor who looks like a master - or simply a greedy or egotistical demon disguised as one!
The tea pot holding the tea will vary from situation to situation, too. It may be cracked (and not hold all its tea); an heirloom treasured, protected and passed down in a family for generations (and thus of greater value than all except the learned appreciate); expensive (and worth it - or simply over priced!); hard to come by (you have to look long and hard for a really good teapot!); common (adequate enough and satisfying those satisfied with easily obtained tea pots and wanting one just like everyone else has); plain (but perhaps disguising wonderful properties!) or over promoted. Care needs to be taken in judging a teapot! We all receive tea - and, so did our teachers! We must ask what was/is the state of the cup, the tea, the giver and his motivation, and the pot in both transactions - our teacher's and our own. One must see many cups, many teapots, sample many teas to know good tea from bad, pure from impure, and see and many masters to know false, bad, better, and best. If you appreciate this tea story, you will be the wiser. If not, then I must think that tea thrown on the floor simply makes a mess and wastes the tea!