It's not clear to me

 What is the meaning of color? 

What is the color of light? 

Why are some things clear, some things translucent and others opaque?

Some sharp-edged and others softly spontaneous?

 In our house there are approximately 200 drinking vessels. Cups, mugs, glasses and so on. We have our favorites, and I've noticed when my relatives come to visit, they grab the same glasses that we like. They do this year after year. No matter if it's mom, uncle, sister or even friends - only a few pieces get used. Here are the top five:

I could do a scientific inquiry - study the geometry of the cuts in the glass decoration; analyze the color of the glass (did you notice they are different?); compare the weight of the base, thickness of the walls, and the capacity of the vessel; make a study of the shape of the glass compared to the size of the hands; decide whether temperature of the fluid makes a difference; or discern if diameter alters the ability of a nose to sniff the beverage.

But even knowing all these things might not tell me why my family likes these best out of the 200 they have to choose from. Since these glasses are my favorites too, I have often hidden them in the back of the cupboard to reduce the risk of shaky-handed, elderly family members. But to no avail - they will push their way through rows of other glassware to sneakily extract these (while knowing I fear for their safety).  No matter what the beverage - water, milk, orange or tomato juice, wine - these glasses do most of the work.

How do we explain it? Quantity vs Quality? Aesthetic vs Efficient? Cold hard logic vs Touchy-Feelie Emotion?

My wife says "Stop trying to analyze and apply math to everything. They choose those glasses because (1) they look nice and (2) they feel good in your hand."

Any transparent / translucent / opaque portable container (cupped fingers of your hand to ladle to jug) can convey a liquid to your lips. Making the process enjoyable is something else altogether.