SSH login always on? is it safe?

Hi, I have a mbp and I was thinking about leaving my Remote (SSH) Login option turned on all the time since it would be nice to access my machine while I'm away, from another machine. Is this safe thing to do? My login password is 13 characters long and someone would need my ip address AND my password to access my machine without my permission, right? If I were away how would I see my ip address? I would assume it is static, correct? So there would be no need to worry about that. Any thoughts on this?