Comfortable at work

I feel really comfortable with my new co workers.  It usually takes me quite a while to feel comfortable with people, especially in groups, especially when that group already knew each other and I am the new kid.  But with my new co workers, I felt comfortable pretty quickly.  We mess around and joke and talk.  Today we had this meeting to go to and there were a bunch of people.  But most of my staff team was there and we took up a majority of the people at the meeting.  This made me feel comfortable because they were all there.  I felt supported I guess.  I was able to speak up in the meeting.  I was just thinking that it is cool that I feel comfortable with them already and it's only been three weeks.  They are pretty cool.  But it's also a big change in me that I let myself be comfortable.