How stup�d are these non-MusIim terror�sts?

OK, so a lot of people here point out that terror�st attacks are carried out by non-MusIim 'agents' who try to give IsIam a bad name. Which is obviously true. Because we love scapegoats. Now, I was just wondering. How stupid can one be to blow oneself up to give a religion a bad name? What exactly are they trying to achieve and do they realise that they won't live long enough to see their achievements?