have you have some abstract nouns (+20)

Some abstract nouns are countable, while some are not. When you have doubts, consult a good dictionary.

I have a meeting. I have two meetings. (meeting is an abstract noun, countable)
I have experience in teaching English. (experience is an abstract noun, uncountable)

The use of "the" in front of abstract nouns has nothing to do with the property of the noun (abstract vs concrete, countable or uncountable), but rather whether the noun is qualified or specific.

John has kindness.
John has the kindness to let us stay overnight at his place.

Mary has many good qualities.
Mary has a quality that Jane does not have - patience.
Mary has the quality to play the piano very well. (assuming that there is a specific quality)
Mary has the qualities to play the piano very well. (assuming that there are multiple qualities)

happiness, saddness, illness
improvement, compliment
friendship, ownership
fever, power
champion, union, relation