Close your eyes for a moment. Remember a summer afternoon when you were seven. You might recall the sticky sweetness of a melting popsicle, the blinding brightness of the sun, or the pure, unbridled joy of riding a bicycle.
Now, think about a Tuesday afternoon three weeks ago. It’s probably this flurry of emails, traffic, and routine.
We tend to look back on our childhoods with rose-tinted spectacles and assume that life was objectively better back then. It’s tempting to dismiss this as mere sentimentality, but neuroscientists and psychologists say there are hard biological truths at work. We were not just happier because we had less money to shell out; we were happier because our brains were different sorts of machines.
The primary reason childhood feels so electric is the sheer density of new data. To a child, the world is an alien landscape waiting to be mapped.
When we experience something for the first time (seeing the ocean, tasting cotton candy, learning to jump rope), our brains release a massive surge of dopamine. This neurotransmitter is the brain’s reward signal. In childhood, these dopamine spikes happen constantly because everything is novel.
"As adults, we suffer from 'habituation.' We have seen the movie before, so the brain stops paying attention to the plot twists."
As we age, we fall into habituation. The brain is an energy-conserving organ; it stops releasing high levels of dopamine for routine events. This explains why a childhood summer felt like an eternity (it was packed with new neural encoding) while an adult year flashes by in an instant.
If you look at an MRI scan of a child’s brain versus an adult’s, the most striking difference is in the Prefrontal Cortex (PFC).
The PFC is the CEO of the brain. It handles executive functions: planning for the future, calculating risks, social inhibition, and worrying about consequences. In children, this area is under construction.
While this makes children impulsive, it also grants them a superpower that adults pay thousands of dollars to relearn: true mindfulness. Without a fully active PFC, a child is not ruminating on yesterday’s mistakes or stressing about tomorrow’s meeting. They are biologically locked into the present moment. Their happiness is pure because it is unburdened by the concept of "later."
Why do you remember the family road trip as a glorious adventure, but forget the motion sickness and the arguments in the backseat? You can thank a phenomenon known as the Fading Affect Bias (FAB).
Research suggests that our brains are biased editors. Over time, the negative emotions associated with memories fade much faster than the positive ones. It is a psychological immune system to keep us resilient.
What's more, childhood memories are formed in the Amygdala—your emotional centre—as well as Hippocampus, also known as the part of brain that deals with memories. Because childhood experiences are often deeply, highly emotional and high stakes—they lay down deep, durable neural pathways that the banal spreadsheets of adult life can’t even hope to match.
Finally, nostalgia provides such a powerful shield. Today’s adults suffer from “decision fatigue” and never-ending uncertainty.
When we look back on our own childhood, we feel safe not only because our parents kept us out of harm’s way, but also because that time is over. We know what happens in the story. For one thing, there certainly was no such thing as anxiety in the past.
Nostalgia can carry us back to a time and place where the rules were simple, the colors brighter, and the future seemed like an endless field of dreams. We are missing the glee of our childhoods, but we’re also missing the biology of how we were able to do that so incredibly.