Waiting on people certainly is no easy task, so cut yourself some slack. As to whether you're grown or not...?
Here's a "serving" horror story for you: Years ago when I was in the military aboard ship, I had done something wrong and wound up being assigned to be a mess cook in the Officers Ward Room. It was lunchtime, and we had to transport the food from the galley which was amidships, to the wardroom which was aft.
The head cook was bitching about getting the food down there, and soup was being served with salads. In an effort to expedite this process, I made a count of heads that had no soup and hustled back to the galley, grabbed two bowls of soup and made my way back.
As I moved along the passageway, the bowls began burning my hands terribly. I got through the doorway, and quickly sat one bowl in front of a junior officer, and then turned and went to put down the other in front of the Captain.
As I attempted to set it down, the bowl tipped, dumping the entire contents into the crotch area of the Captain. He made what sounded to be a stifled scream, his face seemed to go from red to a purple and he pushed his chair back with great force, headed for the door.
There was a look of shock among the officers at the table, and now the head cook, was really pissed. Later, I went up to his cabin and apologized.
The next day, I was back out on deck chipping paint.