Which is fine, but for the uninitiated they can translate this into disinterest. Make sure she's not confused. In some sense you're better off actually saying s

Which is fine, but for the uninitiated they can translate this into disinterest. Make sure she's not confused. In some sense you're better off actually saying something along the lines of what you're thinking; quite literally "it's not you, it's me - I need to go recharge my batteries". It's also useful to figure out a way to be alone together. Instead of 2 hours expecting a conversation the whole time; structure it as maybe 4 hours with intermittent conversation, mostly doing your own thing, but in a shared space.