If you have a business or product idea, and you’d like to investigate it further, then it may be helpful for you to write it down. It’s a good idea to keep multiple copies of your ideas — electronic (backed up, on a computer, and in cloud storage), and as physical copies. You may also want to write a will, and instruct on how to access the business ideas, and your wishes for how they may be used when you die.
If you have the time to develop the idea further, check whether there is an existing patent on it, and if so, what the limitations for you developing you idea are. Analyse demand for the business or product idea by doing market research. Check to see if there are existing businesses offering the idea. If there are, could you better serve that market demand through better quality, service, or value? If there aren’t (or even if there are), do surveys, interviews, and so on, to get a better understanding of whether people would want to use the product or service, and how much they’d be prepared to pay, if anything.