What were your first days in the military like? What is a memory from that time that really stands out for you?

That's easy. Reception Center. It was a well-oiled, well-run mad house.
http://jackdurish.com/jacks-blog/welcome-to-the-army

My absolutely very first memory is when, after the bus I was on pulled into MCRD at what seemed like 10pm (it was fully dark outside), the DI got on the bus and changed my life forever. I can still remember what seat I was in and the fear I felt :)

I knew right away I wasn't in Kansas anymore (to borrow a phrase) :)

And I remember my first mass-produced breakfast the next morning. Well, I remember the smell and that we weren't given much time to eat it.

Being yelled at a lot and having to double time everywhere. I'd do it all over again if I could.