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.
Seeing pictures of my old friends made me feel very nostalgic. They remained nostalgic about the good old days. [+] more examples [-] hide examples [+] Example sentences [-] Hide examples