John 4:13-14 (NKJV)
Jesus answered and said to her, "Whoever drinks of this water will thirst again, but whoever drinks of the water that I shall give him will never thirst. But the water that I shall give him will become in him a fountain of water springing up into everlasting life."
I have found that I really don't like the taste of water if I am not thirsty; I'll drink soft drinks or tea but not much water. One thing I have noticed however, when I am really thirsty, nothing satisfies like a cool drink of water. We need water to live. You can go for many days and even months without eating, but you can go for only a matter of a few days without water.
Jesus is obviously not talking about physical water but is speaking by analogy to some sort of spiritual satisfaction. The world is looking for satisfaction but what they find never seems to last or really satisfy. They search in the wrong places. If they only knew how desperately thirsty they were and how much Jesus could satisfy their deepest need for a fulfilled life. People need Jesus.
Psalm 34:8 (NKJV)
Oh, taste and see that the Lord is good; Blessed is the man who trusts in Him!