The sentence "You will remember that I remarked the other day that for strange effects and extraordinary combinations, we must go to life itself, which is always far more daring than any effort of the imagination" appears to be included by the author to emphasize the idea that real-life experiences and events often surpass the creativity of the human imagination.
The author is likely using this sentence to make a point about the unpredictability and complexity of real life. It suggests that when trying to understand or appreciate strange or extraordinary occurrences, one should look to real-life situations and events, as they can be more remarkable and unexpected than anything that can be invented by the imagination. Essentially, the author is highlighting the richness and unpredictability of life and how it can provide unique and astonishing experiences that surpass what we can dream up in our minds. This sentence serves to underscore the theme of the unpredictability and intricacy of real life in the context of the author's work or discussion.