Embarrassing Work Blunder

I've been at my new job for a week and a half, and there have been a lot of problems configuring my computer so that it has all of the necessary programs. Today, my computer was finally complete, but the keyboard was all messed up so that I had to hit the control button instead of 'enter.' That kept throwing me off all day. But, I finally had access to the mainframe on my computer. Navigating through the mainframe is kinda weird. To move from screen to screen, you have to type a string of letters or numbers which will correspond to a specific screen. The letters don't make any sense. To get the the main screen when you first log in, you type 'SPF' onto a blank screen. I thought to myself, "Just remember, it's three letters, begins with an 'S' and is associated with sunscreen." So, later in the day the boss came into my cubicle to show me something on the mainframe and asked me to log in. I was working on a couple of other things, so I was a bit out of it when he came over. I logged onto the mainframe, and without thinking, my fingers just typed in 'STD.' I hit enter, and nothing happened. The boss looked a little confused as he peeked over my shoulder.

Me: "Oops! My keyboard is all messed up. I have to hit control for enter."

(I hit control, and still, nothing happens. I couldn't tell if the boss was embarrassed or sincerely confused, but now he finally decided to clue me in.)

Boss: "STD?"

I was so mortified.