Drawing from imagination is actually drawing from memory.
It can be, but it isn't really. Most folks can do a landscape or a general person from memories of what earth and people look like, in general. Few people can put their mother in a surrealist scene working from memory, though.
The imaginative part does depend on memory and experience and a good knowledge base. But once you have the idea, you might want to actually do research and work from reference photos.
But you might want to look up what a snake looks like if you want to make it look like a realistic snake. Same for other animals - there is a limit to the details humans tend to remember. You'll remember more if you specialise.
For example, these are mine. The first used numerous reference photos, the second many different koi photos, and the last, an onion.
By "drawing from imagination" I meant drawing without a reference (live or otherwise). You point seems to be: "drawing a very realistic rendition of an object/subject without looking at it is hard". Which is true, but completely orthogonal to my thesis that "drawing from imagination == drawing from memory".
On a tangential note: there's more to creating believable art than accurate re-creation of proportions and details (which is why sites like deviantart are full of completely lifeless art that immediately reads as copies of photos). I'm aphantastic and only a have a very general idea of what a bear looks like, but I'm pretty sure I could draw a move convincing one "from my head" than someone untrained spending all day at the zoo would, because I have a good knowledge (or memory, if you will) of dogs and cats musculoskeletal anatomy I can extrapolate from, and I understand how forms in space and light work.
It can be, but it isn't really. Most folks can do a landscape or a general person from memories of what earth and people look like, in general. Few people can put their mother in a surrealist scene working from memory, though.
The imaginative part does depend on memory and experience and a good knowledge base. But once you have the idea, you might want to actually do research and work from reference photos.
But you might want to look up what a snake looks like if you want to make it look like a realistic snake. Same for other animals - there is a limit to the details humans tend to remember. You'll remember more if you specialise.
For example, these are mine. The first used numerous reference photos, the second many different koi photos, and the last, an onion.
[1] https://www.deviantart.com/disgruntled-peon/art/Fortunate-Si... [2] https://www.deviantart.com/disgruntled-peon/art/Things-by-th... [3] https://www.deviantart.com/disgruntled-peon/art/Sour-Onion-6...