Password not complicated enough?

I'm trying to change my password to make it more complicated than my current one. It meets all the security criteria - i.e. alpha numerical, at least 8 characters long and contains upper and lower case. Apparently it's not complicated enough despite meeting all the criteria it needs.

I could make a completely different password altogether, but the idea of a password is it's one I choose and am going to remember. If I can't use the password I want, I'm not going to remember it!