My little brain can't keep up with too many things either, which is why I only use statically typed languages.
Dynamically typed languages force me to keep type information in my head, and that's just not a good use of my brain when the compiler can be so much better than me at this.
I don't want to take a side in the dynamic vs static typing debate, specially since my favourite languages are Common Lisp and OCaml and it would be difficult for me to choose either, but I wouldn't say your argument of having to keep everything on the head holds if we consider the whole array of dynamic language offerings.
Compared to toys like Perl, Ruby, Python, etc., proper dynamic languages (Lisp, Smalltalk) have state of the art debuggers, browsing and discoverability tools and let you backtrack, experiment and tweak your program in an iterative fashion. They are indeed "little brain" friendly and the development experience matches or surpasses those of compilers and classical IDEs.
I am so much more productive in LispWorks than, say, IntelliJ+Java it isn't even funny.
Dynamically typed languages force me to keep type information in my head, and that's just not a good use of my brain when the compiler can be so much better than me at this.