Opportunistic infections (OIs) are infections that occur more frequently and are more severe in individuals with weakened immune systems, including people with HIV.
Being nostalgic means to miss the past time. It seems that a real life was in the past because now in the present is different, probably things changed and we know that never is going to be the same. It leads to a nostalgic feeling.
The term feeling is a verbal noun denoting the action of the verb to feel, which derives etymologically from the Middle English verb felen, âto perceive by touch, by palpation.â It soon came to mean, more generally, to perceive through those senses that are not referred to any special organ.