Childhood Traits in Adulthood

Tell me about a childhood personality trait and how it has matured/changed/manifested in adulthood.

For instance, when I was about 11 or 12, my family were sitting around the table one day talking and joking about familial nick names, who had them, what they were etc. and my dad looked me square in the eye and said, “You’re ‘The Instigator’, you get people to do things they shouldn’t do and know better than to do and then run just far enough away to not get in trouble and just watch what happens.”
Today, yeah, I can see that sort of, in myself. Not to cause trouble though, more to get a job done at work, or try to help someone see past perceived limits or figure out how to get around some obstacle to their goal. “If I can learn to do it, so can you” is a frequent utterance of mine when working with a new person or helping someone such as Mrs.Guest achieve a goal.

The scientific term for a new-born critter is “neonate”, and the corresponding adjective is “neonatal”.

It’s a known and well-observed fact that neonatal animals change as they grow up, but some retain some of their juvenile characteristics more than others. (This refers in particular to behavior, rather than physical traits like facial proportions.) Playfulness is especially a noted behavior of neonates that tends to disappear in whole or in part as the animal matures, particularly in mammals.

Consider cats for example. Kittens are known for being very playful. That’s why everyone thinks kittehs are so cute. As they grow up, they become less playful and start taking life more seriously like a proper predator should.
The trouble with a kitten is that
Eventually it becomes a cat.[indent]-- Ogden Nash[/indent]
Contrast with dolphins. Dolphins remain very playful throughout their lives. It’s one of the reasons that people who work with them think they’re so much fun. This characteristic, of retaining juvenile characteristics throughout life, is called neoteny, and seems to occur (or not) to different degrees in different species.