Why do we copy the crowd when we don't know what to do?
When you're unsure, other people stop being company and start being evidence.
Social proof is the tendency to look at what others are doing and treat it as the correct thing to do, especially when a situation is unfamiliar or ambiguous. The less certain you feel, the more weight the crowd's behavior carries. You aren't just trying to fit in - your brain quietly assumes that if everyone is acting a certain way, they must know something you don't.
You open a food app, see two noodle shops, and pick the one with 2,000 reviews over the empty one - even though you've tasted neither.
Uncertainty is the trigger: the murkier the situation, the more you outsource the decision to whatever the crowd is doing.
Once you can feel social proof working on you, you can pause and ask 'do they actually know more, or are they just guessing too?' before following the herd.
No map of your own, so you follow the footprints already in the sand.
Learn the idea and practice English at the same time.