Optimistic: Buat keindahan hidup (For the beauty of life)
Pessimistic: Menjadi hamba persepsi mereka yang lain (To be the slave of others' perception)
This sentence is in complete ..it does not say exist in their sentence .. once again incorrect translation from duo ..thi sentence only says ..why do i ..why are i .. nowhere in the sentence does exist .. exist excuse the pun
'Ada' here serve as a verb, means in english 'to be exist'. Meanwhile, it is true that in some sentences 'ada' could be translated as 'is/am/are/do/does/to be'.