Final answer:
Galaxies take a long time to reach their current distance from us because we are observing them from the past.
Step-by-step explanation:
When observing galaxies from Earth, we are essentially looking into the past because the light from distant galaxies takes many years to reach us. The time it takes for light to travel from a galaxy to us is equal to the distance in light years.
For example, if a galaxy is 2 million light years away, the light we see from that galaxy left it 2 million years ago. So, the time it has taken any galaxy to get to its current distance from us depends on the distance in light years.