Dale Carnegie, author of the classic book "How to Win Friends and Influence People," once said, "Act enthusiastic and you will be enthusiastic." While gaining a real sense of enthusiasm takes a little more work than that, embracing Carnegie's attitude can get you started.

Evaluate your current attitude before you try to be enthusiastic. Take a full inventory, especially focusing on where you're negative or pessimistic. Then study where you already have some enthusiasm.

Determine what's behind any negativity and attempt to correct that as you work on increasing your enthusiasm. When you're experiencing challenges and setbacks in life, it's difficult to be enthusiastic. A life coach or a counselor could help you change things.

Cultivate a positive, optimistic attitude by examining where you're already enthusiastic. Meditate upon your current enthusiasm and positive spirits a few times a day. Over time, you should find your enthusiasm increasing.

Seek out things you're genuinely enthusiastic about. Start with what you're already enthusiastic about, and find similar things to add to the list. Joining groups that share your interests, either online or in person, is one easy way to find what you're enthusiastic about.

Spend time with people who are sincerely enthusiastic and have no problem expressing it. Being around this sort of person can make it easier to display your own enthusiasm.

Change your behavior to reflect enthusiasm. Instead, if you feel enthusiastic on the inside, let it come to the outside.

Widen your circle of enthusiasm. The more things you can find to be enthusiastic about, the more enthusiasm can become your natural trait.