I'm going to ask how old you actually are before I point out all the flaws in what you said about growing brains,

[aw nawr]

...But that's definitely not good enough reason. A person's ability to be responsible falls on their mental capacity it's true, but it falls on their life experiences as well. And I don't mean as a quantity either. You could spend fifty years living a certain way and the result would be someone who can't be left alone for more than a few minutes, for example.

[......

........He's squinting. ...And...it definitely went well for you..?

[Look can you fault him for being suspicious here?]