He struck at you because you were an easy target. A warm mouse compared your or warm hand, your hand is a much larger target. Just keep that in mind. Also, some bps can be temperamental about being bothered in their house. Once you get them out of the tub/tank, they are usually fine. There aren't a whole lot of bps that will strike at you for bothering them, but I have a couple-so it does happen. If he's in a defensive pose just touch him on the head with your finger if you are brave enough-or something else that is soft, it usually startles them enough to stop being so defensive and you can pick them up.
Other than that, my only other comment is that snakes aren't like cats or dogs, even rats. They really don't bond with anyone. They are very instinctual, and don't really care if they have a "friend" or not.
In the end, have fun and enjoy your new pet!