I stumbled upon this wonderful quote while reading the autobiography of Benjamin Franklin. Allow me, for a moment, to write a little fuzzily.
I think this really is one of the more optimistic quotes I have ever read. Getting wet from rain can be a little uncomfortable at times, but really, as long as you can huddle together, it can make for an amazing moment.
"As wet as water could make us" is a beautiful way of saying that they were really wet, but that that wasn't so bad. Even more fuzzily: Really, water can only get you so wet. There are way worse things in life and I find this an eloquent way of phrasing that.