system
Given the following post, respond as if you're commenting on Reddit:
human
Why is the CMB radiation not only always around us, but ALWAYS with us?

As far as I understand, the CMB is the result of the recombination, that is when the photons could finally travel freely.

If all the photons "escaped" at more or less the same time, why are we constantly "seeing" these photons? Shouldn't they go past us and then be gone to further places in the Universe? 

Light from the stars is different because stars are constantly producing this light and that's why we can observe it in a constant fashion. However, the moment of recombination is not constantly emitting light because it is that, a moment. So I am very confused.
gpt
It's due to the finite speed of light, and the infinite (or really big) size of the universe.

Imagine an experiment where you set up a huge array (say, filling the solar system) of flashbulbs set to all go off at the same time.  When they go off, you'll see the flashes from those close to you first.  Then those ones will appear dark, because their light will have passed you by, as you said.  A second later, the light from the bulbs the distance to the the moon (or so; ie a light-second away) will be reaching you;  you'll still see light, just from those bulbs rather than the ones close to you.  And so on, and so on - as each second passes you'll see light from bulbs that were another light-second away.

With the CMB, we're looking out at the inside of a sphere, known as the "surface of last scattering", which a certain distance from us.  That sphere, ie the distance to the "lightbulbs" (really electrons last scattering photons at a particular time in the universe's history, happening at the same time everywhere) we see is growing by one light-year per year.  We're always seeing a little further away as time passes;  the same moment over and over again, as it played out further and further away.