Why do We Believe in Lottery?

I remembered I bought a few lotteries when in junior school. And my teacher found them. She gave me a long and deeply moralism. In her theory, it's a thought of reaping whitout sowing. I didn't get any rewards from the lotteries, except for the theory. I didn't buy lottery for a very long time then.

Do I believe in reaping without sowing from lottery? Yes. But... I have learnt the subject of probability. So, why I buy lottery now is not because the astonishing rewards. I think, I am just finding an exciting feeling, or a wave in my life. A feeling to dream, that I become a millionare. But the most important point is the feeling before the drawing. A ups and downs in my life.