The surface meaning of this statement is straightforward: don't postpone your joy by waiting for future events or conditions to be met. It suggests that the feeling of happiness is accessible right now, rather than being a reward for future achievements or circumstances.

Eckhart Tolle, drawing from various non-dual traditions like Advaita Vedanta and Zen Buddhism, points to a deeper truth. He argues that the "self" we identify with, the ego, is a construct of thought, constantly projecting itself into the future or dwelling on the past. This mental activity creates a sense of lack and dissatisfaction, which we mistakenly believe can be filled by future events. True happiness, in this context, is the cessation of this mental noise. It's the realization of your true nature, which is pure consciousness, already complete and at peace. This state of being, unconditioned by time, is what Tolle calls the "Now." Awakening to this presence dissolves the illusion of a separate self and its incessant desires, revealing an inherent joy that is not dependent on external conditions.

In your life: When you feel a pang of unhappiness, notice if your mind is focused on a past regret or a future worry. Gently bring your attention back to the sensations of your body and the immediate environment, finding the stillness that already exists.