“A dream is a wish your heart makes
When you’re fast asleep”
-Disney’s Cinderella, 1950
During my first year of medical school, on the first Monday of winter break, I slept for 18 hours straight. I woke up to a string of text messages and missed calls from concerned friends, glanced out the window to see pinks and oranges of the sunset streaking across the sky, and then promptly fell back asleep. It should come to no surprise then, that during this final block of medical school, after 4 long years, my days while on discretionary time have been filled with a lot of sleep. I kid you not, I will get a full 12 hours of sleep in a night, and then still find myself needing to take a 4-hour nap in the afternoon (is it even a nap at that point?) It’s been blissful, maybe even more so because I know that I will never really have a period like this again. The start of residency and the rest of my career is fast approaching, and if the amount of sleep my body has been needing this past month is any indication, I need to ensure I have a sound sleep routine in place so I can perform at my best.
That first line from the iconic Disney song has been streaming through my mind this past week, as I’ve been thinking about what it means to dream. Of course, there’s the scientific definition of “dream”—mental, emotional, and/or sensory experiences that take place primarily during rapid eye movement (REM) sleep.1,2 (Fun tidbit, REM sleep was discovered in the 1950s, the year Cinderella was released). Positron emission tomography (PET) data published in 1996 identified that during REM sleep, areas highly involved in emotion (amygdala), memory (hippocampus), visual imagery (posterior temporo-occipital cortex) as well as other cortices have increased neural activity.3 In contrast, a large area of the dorsolateral prefrontal cortex, the center for planning, decision-making, and executive voluntary control, has decreased activity.3 These findings suggest that REM sleep, and dreaming by association, helps with memory consolidation, emotional processing, mental “housekeeping” of information, and reviewing/analyzing the day’s events. There is still much debate amongst sleep experts on the purpose of dreams.1
So, dreams seem to offer a functional role for our brains, yet the content of our dreams hardly seems to correlate with what actually occurred in our day, e.g. running for my life from a dinosaur skeleton in a temple ruin does not really reflect my day of sitting in a lecture hall trying to follow along an endless number of slides. This is where dream interpretation comes into play, in which there are many different approaches and theories to this. For the purposes of this piece, I’m not going to dive into the various approaches to interpreting dreams (Freud, I’m looking at you), though I welcome people to offer their interpretations of why my brain seems to interpret learning lecture content as a life-threatening scenario.
Instead, I want to focus on the kind of dreams that Cinderella was singing about. “A dream is a wish your heart makes.” Of course, the Disney princess wasn’t referencing some physical biochemical process of the heart that generates our dreams for life. And yet, I think there is a strand of truth in the sentiment. During our journeys through life, our experiences, interactions, and relationships shape what we wish for in life, and give us shimmering pieces that form our dreams over time. The possibilities are endless, because how we arrive at wanting that dream is uniquely individual. Perhaps that dream is to write a book, or perfect baking sourdough bread, learn how to play the piano, become an art teacher, live in a beach house in Malibu, or fly to the moon! Maybe it’s to become a doctor, and match into your dream residency program. And while I do believe a small component of achieving those dreams can be attributed to luck, prayers, and a sprinkle of magic, I also do not want to diminish the hard work and dedication that goes into making a dream a reality. The second half of the line in the song, “when you’re fast asleep” has merit both physiologically, when dreams manifest during sleep, but also in that good sleep is crucial to performing at your very best and setting yourself up to be able to attain those dreams.
With that in mind, what are some things you can do to help get optimal sleep? There’s a lot of different things you can implement to help with this, and I won’t cover all of them, but here’s some of the heavy hitters4:
· Limit screen time at least 60 minutes before bedtime
· Establish bedtime rituals, such as reading, listening to calming music, or taking a warm bath or shower
· Stop caffeine intake by 2pm at the very latest, ideally by noon
· Try keeping to a consistent schedule of going to bed and waking up at the same time
· Get regular exercise, aim for 150 minutes a week
· Avoid nicotine, which is a stimulant, and alcohol, which can create an effect of alertness as it leaves your system
· Keep your bedroom dark and cool, between 60º F – 67º F
· Get some direct sunlight shortly after you wake up, which can help steady your circadian rhythm and aid in sleep at night
Personally, over the remaining few weeks I have left before residency starts, I’m aiming to be more disciplined with limiting screen time and keeping to a consistent sleep schedule. I hope these strategies help you find the rest you need as well. After all, if a dream truly is a wish your heart makes, then we owe it to ourselves to make sure we’re fast asleep to catch it.
References
1. Dreams: why they happen & what they mean. Sleep Foundation. October 30, 2020. Accessed May 2, 2026. https://www.sleepfoundation.org/dreams
2. Siclari F, Valli K, Arnulf I. Dreams and nightmares in healthy adults and in patients with sleep and neurological disorders. The Lancet Neurology, 19, 849-859
3. Maquet P, Péters JM, Aerts J, et al. Functional neuroanatomy of human rapid-eye-movement sleep and dreaming. Nature. 1996;383(6596):163-166. doi:10.1038/383163a0
4. M.D DB. 13 healthy sleep habits. UT MD Anderson. Accessed May 2, 2026. https://www.mdanderson.org/cancerwise/healthy-sleep-habits.h00-159778812.html
Kathleen LeFiles is a medical student from the Class of 2026 at The University of Arizona College of Medicine - Phoenix. She graduated in 2020 from The University of Arizona in Tucson with a degree in Physiology and a minor in Care, Health, and Society. When she's not studying or writing, Kathleen enjoys practicing Pilates and yoga, frequenting local coffee shops, and listening to pop music. Feel free to contact her @kathleenlefiles on Instagram or email at klefiles@arizona.edu.