I've sometimes noticed myself giving ideas in passing during a friendly conversation where nobody is defensive, my idea is passed over initially, but some days

I've sometimes noticed myself giving ideas in passing during a friendly conversation where nobody is defensive, my idea is passed over initially, but some days later the person has the same idea and doesn't remember that I suggested it. This might be some kind of bias on my part though. Point being: Offer your idea during a friendly time where it will not cause the other person to be defensive and then you have to wait. You might find that the next time you bring it up the person is more receptive.