says...

A time machine

If you could invent anything, what would it be? Obviously a Time Machine! It’s amazing! The reason why it’s amazing, wonderful and interesting is because you could see how the past was and how they felt in the olden times, how they lived without any technology. Best of all, you could see and have more time with your amazing grandmother and your wonderful grandfather.

Not just seeing the past! But you can actually see the future, the incredible future. For example, you can see how beautiful or handsome you are going to be. Best of all you can see if technology improves and go further.