Self-Serving Bias
Self-serving bias refers to people's tendency to attribute positive outcomes to personal factors, but attribute negative outcomes to external factors. In other words, "If it's a success, it's because of me. If it's a failure, it's because of someone or something else."
For example, if I met my sales target, it's because I'm a great salesperson. But if I did not meet my sales target, it's because the economy is bad.