For example, my ex-boyfriend always boasted and bragged about how good he was at everything and that there was nothing he couldn't do. Whatever you named, he swore he could do it and as he clung to that belief so strongly, his overconfidence led him and I to believe it was true. It made me overestimate his abilities that he could do just about anything I named. One thing I can say is that he was good at football and excellent at maths, and he worked very hard. Although, in basketball, golf, money management, and some other things I witnessed, he was horrible. His confidence level was so high that whatever you said he couldn't do, he would tell you he could. In some cases, however, it's good to have confidence when you know what you're talking about; too much trust can be bad