I would like to know the meaning of "it puts things into perspective".
Dave Talley, a homeless man who lives in Tempe, Arizona, found a backpack containing $3,300 in cash. He turned it into a local social services agency:
The temptation to keep the money was almost overwhelming, he said. Then, his conscience kicked in.
“The reality set in that it wasn’t my money and it needed to be turned over,” he said.
Inside the backpack was a flashdrive with a resume belonging to Bryan Belanger, a student at Arizona State University and the owner of the backpack:
“It’s humbling, and it puts things into perspective,” Belanger said of Talley’s decision. “From his point of view, he could’ve taken care of himself by paying for rent or something with that money.”
For example, you might be worried that you don't have enough money for a new laptop computer. Then you watch a TV show about people living in slums who can't even afford to eat. You might say to yourself: "That puts my problem into perspective."
In the case you mention, the student might have been thinking, "All people are selfish and only care about themselves". Then this happens, and he realises that some people actually care. It puts his thoughts into a proper perspective.