When you were a preschooler, your favorite "Star Trek" character was Ensign Chekov. You often asked to watch "Chekov episodes" on our "Star Trek" DVDs, and liked to play with that action figure - or when we didn't have that action figure, you'd just pretend another one was Chekov!
Did you know that Chekov wasn't in the first season of "Star Trek"? His character joined the crew in the second season, and he's not in every episode of the second and third seasons. He's not in any of the cartoons but is in all of the movies.
I'm not sure why you liked Chekov so much. I suspect it's because he was the youngest of the Enterprise crew and a bit boyish compared to the rest, so you probably related most to him.
Here's a website page about Chekov!