I don't trust anyone 100%, not just boyfriends.
There's always a very small part of me with a defence mechanism ready to expect the worst. I have had my trust thrown back in my face in the past, but I also don't like to tarnish others with the same brush. So what I'm saying is I'll always give someone the benefit of the doubt in the hope that they won't let me down. After all, that's the civil thing to do!
And also, I would rather be able to open my heart and love fully, than to be sceptical about it and not feel true love at all.