Henophobia

Unophobia (from Latin unus, "one") is the fear of number one. Sufferers would often associate this with monophobia (from Greek mono, also means "one") or uniphobia, the fear of being the only one, meaning unophobes would not be alone. Some sufferers of unophobia may fear being the number one in a certain category, especially in the dubious category. Unophobes may panic upon thinking that people live only once as well as being anxious about the phrase 'once in a lifetime'. If the sufferers get involved in some specific special events for the first time, they would do it again, such as vacating to same destinations multiple times or getting married twice.