Surrealism?

My understanding of speculative design is basically that the designer does not have to be bound by the regular constraints of design, designers have the opportunity to think up the most ridiculous products or systems without consequence of the real world. For example living on the moon is a completely acceptable concept in the world of speculative design.

But the idea of speculative design sounds ridiculous. Why in the name of God would a designer think in this manner when this kind of thinking obviously leads to no design when it is intentionally impossible? The thing is though, if we were to always think within the boundaries of the current world, how are we to develop? Speculative design helps us to think beyond the boundaries and allows to create more freely.

I thought of Leonardo da Vinci who's sketch books were found to contain detailed sketches of a helicopter. Now da Vinci lived in the fifteenth century and the first helicopter was built in 1940. If that can't be considered speculative design then I don't know what is. Clearly he was thinking outside the box, he knew that it wouldn't work mechanically but he dreamed of the technology that would allow flight.

This concept of design can be useful for some designers or artists who may find it difficult to think creatively when considering all that they have to be mindful of. I usually find it difficult to think freely when constrained to a brief, I know that I'm too 'precious' about by sketching and ideation, I find it hard to let my creativity flow, I will have to think twice about the ideas that spring to mind and then choose whether to draw them or not, when I should be documenting everything that I can imagine. Even the simplest, most ridiculous idea could develop into a solid concept.