Translation:When I surf the internet, I find many interesting things.
"I find that a great part of the information I have was acquired by looking up something and finding something else on the way." — Franklin Pierce Adams
Google and Facebook do, Amazon and Microsoft know a good chunk too.
Including every single duolingo lesson you've ever taken. (for at least Google and Facebook)
-um is a sort of catch-all suffix and ret- = net. So retumi becomes: "to do (something) on/with a/the net" "to web surf" is a reasonable translation. Did you tell the management?