Great ideas are everywhere! But you don't need good or even great ideas to make a startup, you need something that a VC will fund and that a big corp will acquire. Analyze that field and surf the gradient.

Find whatever huge entity with lots of cash is throwing that cash around and figure out how to make something that the cash will stick to.

Over the years it has been Autodesk, Microsoft, IBM, Cisco, Softbank, etc.