ADHD has been more prominent in recent years. I believe there are circumstances in our environment that highly contribute to this, as well as possibly more attention from medical institutions and other interested players (pharmaceutical industries, for example).

In any case, in an effort to better understand this condition, I went to Gabor Maté's Scattered Minds. Some passages were particularly enlightening as to how ADHD feels like.

A well-put definition of the adult ADD mind.
ADD personality as a juggler that cannot stop
a description of the life accomplishments of an ADD individual
the constant chaos of the the ADD's surroundings
the aversion to boredom; the ceaseless white noise in the brain
a brilliant definition of the ADD state
the forgetfulness of the ADD brain
an inability to finish plans, goals, tasks — the idea of permanent potential
the self-recognition in the ADD diagnosis
the vast array of activities the ADD person undertakes
An incapacity to consider the future by the ADD person
some consequences of the emotional intelligence underdevelopment
the use of EEG studies on ADD brains
an analogy to explain the underdevelopment of the ADD brain
the relationship between (hyper)sensitivity and ADD
the effect of Ritalin in the brain
a possible pattern for parents of ADD children in relationship to the family
the eye-sweeping in the ADD person
the purpose of the sensitivity trait