You can almost imagine this as sort of developing a 6th sense... you'll be able to "feel" each others thoughts or emotions.  Not explicitly read each others' minds, but "feel" it.  How do you explain what it's like to see to a blind man?  Or what taste is like?  In the same manner we can share experiences with each other and develop this sense of what it's like to "feel" like someone else.

It could be addicting in the beginning - almost like social media and everybody being attached to their phones - we'd try to experience every feeling or emotion that others offer to share.  Instead of exploring ourselves and our own minds, we'd be consumed with the thought of others.

On the other hand, it could be a good thing.  We could share our thoughts so that we can better understand one another.  We'll be able to figure out what love feels like.  Or happiness.  Or anger.  We can work together and perhaps advance exponentially as a society.

This connected society will be viewed as a brain or separate entity itself.  Each of our minds is like a separate neuron firing in the brain of the world.