I am something people love or hate. I change peoples appearances and thoughts. If a person takes care of them self I will go up even higher. To some people I will fool them. To others I am a mystery. Some people might want to try and hide me but I will show. No matter how hard people try I will Never go down. What am I?

age

Explanation:

some people love that they are already at a certain age. Meanwhile, some people try their best to hide it. Often times, especially in Asian countries, people are surprised to learn that a young looking individual is actual in his/her 40s or 50s.

age

Explanation:

including the octave, the answer would 8 notes in a major scale with one note being played twice. ex) c major scale includes: c, d, e, f, g, a, b, c

notice that c is played twice

however, if you were to ask me how many different notes are in a major scale- the answer would be 7.