Limitless Its not so smart

In Limitless, Bradley Cooper becomes the world s smartest man thanks to a new wonder drug. It s actually quite an enjoyable and entertaining film (until the silly ending). However, it s let down by one of those plot contrivances that once read, destroys the film. If he s so smart, why does he think it s a good idea to borrow money from a mobster? I m an idiot and I know not to do that.