With the intuition I have built up over decades of caring for plants, I can "feel" them crying out for water. But that feeling is more a combination of observation and learned outcomes. A dry plant shows, through its color and appearance, that it is thirsty. The same goes for many plant ailments.

As a side note, I live in a rainforest. Just after a rain when the clouds break, the forest is the "happiest". I am sure part of that feeling is happiness I myself feel at the beauty of glittering raindrops on plants and crepuscular rays in the mist. But, the forest feels happy too. The birds are singing and the animals emerge to play in the sun. Truly an amazing feeling.