It doesn't matter how smart you are; to audition for 'Jeopardy,' you just have to luck out and know what they're asking you that day.
Before you begin a thing, remind yourself that difficulties and delays quite impossible to foresee are ahead. If you could see them clearly, naturally you could do a great deal to get rid of them but you can't. You can only see one thing clearly and that is your goal. Form a mental vision of that and cling to it through thick and thin.