Hi! I'm an ISFJ trying to figure things out and while keeping everyone happy. I would describe myself but my MBPT pretty sums it up. Saying "no" is definitely a problem I have and I don't ever give up when it comes to anything especially in relationships and friendships. This is a problem for me when it comes to people who hurt me because I can't seem to stay away from them. I like to make things work but I don't know when to stop. I want people to be happy and if I can't, I see it as a failure.. 
Some non ISFJ tendencies are the following: I find it very boring when there's nothing to do. I want to go out with friends and go do things I've never done before. I am adventurous but only with friends or family. I will never do things on my own. I like to share my experiences with people and the only way for me to be happy is to be with the people I love and care for the most.