A useful construct I find is that of Data-information-knowledge-wisdom
ultimately it is about how it impacts your day to day decision making:

In my classes I give the following example:
DATA
I see a brown block of something on my table, it is square smells nice (all data points)
INFORMATION
putting the data points together, I can be reasonably certain that is a piece of chocolate
KNOWLEDGE
from my experience, when I ate chocolate before I liked it alot, but chocolate is energy dense (another data point)
WISDOM
Given that my goal is to lose weight, I should not eat this piece of delicious chocolate.

It is only when you incorporate information into your knowledge and experience framework and then ACT accordingly, that it becomes useful.

If the data information and knowledge are in your head but you do not make your decisions in accordance with that, all these are USELESS
Strictly defining USEFULLNESS in this case as at an individual level as something that will help YOU achieve your goals by making informed decisions that will lead to ACTIONS that get you closer to your goals.