When was your first memory? It’s an odd question that somehow makes its way into conversations. When I think about it personally, a field of images come to mind, but one age, day, place, or action seems too concrete to pinpoint. I don’t remember being a baby, getting my first tooth, or learning how to walk and talk, but I do remember holding my favorite baby doll, losing my first tooth, and learning how to ride a bike.

According to Carole Peterson, a professor of psychology at Memorial University Newfoundland who studies children’s memories, small children are actually capable of recalling events from when they were as young as 20 months, but these memories seem to fade away by the time they’re between 4 and 7 years old.

“People used to think that the reason that we didn’t have early memories was because children didn’t have a memory system or they were unable to remember things, but it turns out that’s not the case,” Peterson explained. “Children have a very good memory system. But whether or not something hangs around long-term depends on on several other factors.” Peterson believes that two of the most important factors of memory are whether it has emotion infused in it and whether it’s coherent.

This event- or story-based memory is what we typically focus on in relation to “first” memories, but it’s not the only kind. Developmental psychologist Steven Reznick says childhood amnesia “is a rather archaic statement,” since after birth, infants can begin to start forming impressions of faces and react when they see those faces again. This is recognition memory, while the ability to understand words and learn language is called working memory, which occurs around six months of age.

“When people were accusing infants of having amnesia, what they were talking about is what we refer to as episodic memory,” Reznick explained. In order for us to recall events, we need to be able to make sense of the concepts behind them, and in such a language-based way that our adult self remembers information as well.

“For the memory of my brother’s birth, I have to understand the meanings of concepts like ‘hospital’ and ‘brother,’ ” writer Alasdair Wilkins explains.

And what about the idea of a memory that never actually happened? As adults, we often find ourselves questioning whether a memory was real or just something we’ve thought up. False memories do exist, but they begin much later in life. In fact, Peterson conducted a study in which he presented young children with fictitious events in order to see if they could be misled into remembering these non-existent events. But the children didn’t bite. Older children and adults may be creating memories as a result of our need to understand the world.

And have you ever walked into a home, a town, or even a restaurant and suddenly experienced an overwhelming feeling that you have been there before, but can’t specifically remember it? This is another example of recognition memory, which Reznick says is our most pervasive system.

It can start to hurt the brain to try to make sense of the past. We feel it, we make it up, we remember it, and then we don’t. Memories are a beautiful and still seemingly mysterious concept.