There is a famous quote “Everything that can be invented has been invented” believed to be by Charles H. Duell a commissioner of US patent office from 1889. Even though this quote is not accurate, it shows that many people believe the best inventions already exist. Of course, we know today this is not true. Think of the many inventions created in the past 30 years from technology to medical advances.
It is true that new ideas are hard to come by. I often find myself asking, “Why didn’t I think of that?” It seems that all my “good” ideas are already taken. The key is to remember that there may not be many new ideas, but that you can always improve existing products, apps, etc.