If life is “the animate existence or period of animate existence of an individual” (per dictionary.com), or in Robin’s terms, “existing,” then you can’t fail at life. You exist. You just…do. Yup, already a success at the life thing.
If you can’t fail at life, what’s one thing you want to experience, try, do that you’ve been afraid to experience, try, do — because you’ve been afraid to fail? Sure, you could possibly fail at the attempt. However, that won’t ultimately make you or your life a failure — because you’re already successful at life and can’t not be.