Dreamed I was drawing veins that kept turning into rivers

Last night I'm doing a surgical illustration — femoral artery, very precise, the surgeon standing behind me saying 'more red' — and every vessel I ink starts widening into a river delta, the branches turning into actual tributaries with tiny boats on them. I keep trying to label the anatomy but the names keep shifting to place names. Woke up with the feeling you get the hour before a thunderstorm, like the air itself was holding its breath.