Most Americans have at one time or another come up with what they believe is a truly brilliant idea for a product. Whether it’s a new way to iron clothes or it’s just a better kind of a spoon, ours is the land of inventions. However, there is a reason why some products never make it past the idea stage. Sometimes, your idea sounds great initially but when you put it into practice, it suddenly doesn’t sound all that practical. Here are five sure signs that your idea is the proverbial white elephant (i.e. a terrible idea that will waste lots of money and go nowhere):

You Haven’t Thought about Costs

One great example of this is the plan to build the Starship Enterprise. Yes, there really is such a plan out there and no, the first generation version would not have warp drive, photon torpedoes or phasers. It would however be the size of the Enterprise from the original show and would be capable of travel within our solar system. Now don’t get me wrong – I love Captain Kirk and I think the dream of building the Enterprise is a great idea. If I ever became a multibillionaire, I’d probably invest in building some kind of a spaceship myself.

However, practically speaking, building the Enterprise is probably not going to happen in the 20 years this guy wants it to happen because the costs are astronomical. The first President Bush once asked what it would take to go to Mars within his presidency (he assumed he’d be reelected). He was told it would cost around $500 billion and quickly abandoned the idea. So think carefully about your idea. Would people really pay what it would cost to make it? If you haven’t thought about it or the costs are so prohibitive that it’s unlikely ever to be a commercial success, you should probably try something else.

You Haven’t Thought about Your Own Needs

They say that around half of all Americans believe they have “at least one book in them.” In the vast majority of cases, that is exactly where it ought to stay. However, let’s say that you feel that you have the ability to write a book and get it out there. Or you have an idea for some invention but you need to work on it full time for the next two years. It won’t cost much to get going of course, but you need a huge time commitment. Sorry folks but you need to also think about the fact that you’ve got to make a living in the meantime. If you can’t figure out how to make your idea happen without living in a cardboard box on the streets then your idea is not going to happen.

People Nod Politely but Don’t Get It

Finally, you may not want to share your idea with too many people but you should share it with at least some people. Tell them about what it is that you think you would like to create. If nobody understands why you desperately want to create the world’s first machine to combine soap with chocolate spread (because you want a chocolate bath perhaps?), then maybe you should think of trying something a bit more practical.