Sorry to break it to you, but there is a fairly good chance your first memory is a lie. In one of the largest surveys on early memories to date, researchers from the UK found that nearly 40 percent of people have a false first memory.
The latest research seems to suggest that we do not start forming long-term memories until we are around 3.5 years old. The inability to remember events that happened before this point is a phenomenon called "childhood amnesia". Scientists' best guess is that the infant brain is not mature enough, or is too busy developing, to encode life events so that we can later recall them as memories. (Though some say these memories have not disappeared, they are just inaccessible to the adult mind.)
The survey, published in the journal Psychological Science, involved 6,641 respondents who were asked to provide details of their very first memory as well as the age they were at the time. There was just one stipulation – the respondents had to be 100 percent certain it was a true memory and definitely not something they had picked up from photographs, family videos, or secondhand recollection.
The replies suggest the mean age encoding (or memory formation) starts is 3.2 years, but the researchers also noticed something much more interesting – 38.6 percent of respondents claimed to have memories before the age of two. What's more, 893 respondents claimed to have memories before they had reached their first birthday. This shouldn't be possible scientifically-speaking. The implication then is that these first memories are not true memories. They are fake.
To explain this discrepancy, the researchers analyzed the content and language of the memories. Curiously, the vast majority of people who reported these false memories were middle-aged or older (four in 10 people who fell into this demographic had false memories) and herein may lie the clue.