Bravery and heroism but if you are injured, you may not be able to realise your wound and help yourself unless you also have Regenerative Healing Factor. It also may make you apathetic towards those who feel those feelings and develop superiority complex.

Downside is you might also be immune to pleasure.

Not having fear makes you less cautious not feeling pain does not alert you when something is going wrong it is a lot easier for you to die

@Brandon Fitzgerald22 Unless you are also immortal.