It's a good advice, except that... it works the other way around.
You can't figure out that you can't live without something unless you do it. Relentlessly, fiercely, honestly. Do no matter what. Then gradually you may come to realize what this activity really means to you.
If we have to say something, let's say it. If we don't, we still have lots of deep soul-searching to do about our place in the Universe.