Trees

OP is growing cannabis! When in the final stage of flowering, the cannabis plant gets "chopped" by the grower based on their preference of how far along the trichromes are in development.

Roughly, when the plant first starts flowering these trichromes are clear which is a bit early to harvest the bud. When the trichromes are milky is when the THC molecule has fully formulated, and for those looking for the heady sativa-like high this is a popular stage to harvest (as trichromes are able to continue developing during the curing stage). However, it's safest/most common to harvest the plant when a majority of the trichromes are a heavily milky white and just as some are beginning to turn amber/gold/brown. The golden color is when the trichrome has matured enough to begin the breakdown process of THC, which basically become CBD compounds.

This process of clear -> milky -> amber is usually about 3 to 7 days, so OP is surprised it happened so quickly for them!

So as you can see in this picture, the dead center of the image have lots of clearish/opaque trichromes with a significant number of them beginning to turn amber/gold. Looks like a perfect time to harvest and begin letting them cure!