There are several meanings of the phrase “no time like the present.” Conventionally, it means “do it now.” While you’re thinking about it, don’t put it off, whatever “it” happens to be.
More deeply, we realize that we don’t know how much time we have. We don’t know how much of a future there is in this precious life. Life is unpredictable, and no one has a guaranteed life expectancy. We don’t know if we’ll be too sick, or too overwhelmed with some other form of suffering in our lives. If something is meaningful for you, and you are capable of doing it, pursue it now while you can. Express your appreciation for your life through your choices.
Even more profoundly, when you start to pay attention, you realize that the future is a fantasy, and the past is fleeting memory. Past and future live in our imagination, but we’re only alive now. There actually is no other time than the present.