不到底线
[bù dào dĭ xiàn]
'不到底线' means 'never reaching the bottom line'. It implies that this person does not want to or will not get to a point of despair or reach their limits. It might suggest a sense of caution in all kinds of situations. They may believe that it is always possible to avoid going over certain boundaries no matter how close they seem. In general, people who use this name probably do not give up easily.