A word for realising the insignificance of human life against the scale of the universe and enjoying it

Solution 1:

Probably the expression in perspective may suggest what you are referring to: (from TFD)

• within a reasonable view or appraisal. (*Typically: be ~; get something ~; have something ~; put something [into] ~.)

put something into perspective:

• (idiomatic) To compare with something to give a clearer, more accurate idea.
• You can put your worries into perspective when you realise how many people in the world are so much worse off than you.

• The man sitting on a bench compares his woes with the immensity of the universe and this new perspective enables him to have a different perception of himself and his life.

Solution 2:

I think we can call it awe or a moment of awe, and you are in awe of the awe-inspiring universe. That's awesome!

A person who is in awe of a monumental natural wonder, such as a massive mountain peak or waterfall, may feel insignificant. Awe is an emotion comparable to wonder but less joyous, and more fearful or respectful. One dictionary definition is "an overwhelming feeling of reverence, admiration, fear, etc., produced by that which is grand, sublime, extremely powerful, or the like: in awe of God; in awe of great political figures".

In general awe is directed at objects considered to be more powerful than the subject, such as the breaking of huge waves on the base of a rocky cliff, the thundering roar of a massive waterfall, the Great Pyramid of Giza, the Grand Canyon, or the vastness of open space in the cosmos.

http://en.wikipedia.org/wiki/Insignificance (Emphasis mine)

Below is a passage from an article titled "The Power of Awe" that goes in parallel with your example and explains awe in detail:

Imagine you’re standing at the rim of the Grand Canyon with a majestic purple-and-orange sunset blazing across the western sky. You stand transfixed for an hour, then look up at the awesome expanse of stars. You are transformed, lifted, in awe.

B’aima literally means “with awe.” Awe is an experience so powerful that it’s paralyzing. On the other hand, we know awe to be extremely exhilarating. What defines an awesome experience?

When we look at the expanse of stars, we see power, beauty, harmony. We realize that each tiny star is actually a raging sun. And in the face of tremendous force, we feel insignificant by comparison. We realize our own weakness, our smallness, our mortality.

Yet surprisingly, this doesn’t depress us. It inspires us. Because we’re merged with the greater whole. That realization can be a source of tremendous positive energy. And if you know the secret of awe and use it effectively, you can actively release its power in day-to-day living.

http://www.simpletoremember.com/articles/a/the-power-of-awe/

A bonus article titled "25 Awe-Inspiring Reminders Of Just How Insignificant We Are:Prepare to feel tiny":

http://myscienceacademy.org/2013/01/07/25-awe-inspiring-reminders-of-just-how-insignificant-we-areprepare-to-feel-tiny/

Solution 3:

Perhaps the word you are looking for is "epiphany": ( from TFD)

• A sudden manifestation of the essence or meaning of something.
• A comprehension or perception of reality by means of a sudden intuitive realization: "I experienced an epiphany, a spiritual flash that would change the way I viewed myself" (Frank Maier).

Solution 4:

Sonder:

n. the realization that each random passerby is living a life as vivid and complex as your own—populated with their own ambitions, friends, routines, worries and inherited craziness—an epic story that continues invisibly around you like an anthill sprawling deep underground, with elaborate passageways to thousands of other lives that you’ll never know existed, in which you might appear only once, as an extra sipping coffee in the background, as a blur of traffic passing on the highway, as a lighted window at dusk.