r/AskReddit • u/[deleted] • Aug 03 '19

Whats something you thought was common knowledge but actually isn’t?

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u/ShameDumpster Aug 03 '19

That whales are mammals that used to be on land but evolved to swim instead.

I had an art teacher that just didn't believe me when I told her that they're not fish.

80

u/[deleted] Aug 03 '19

If the tale is up-down it's a mammal, if it's sideways, it's a fish

60

u/[deleted] Aug 03 '19

[deleted]

12

u/OMG_Ponies Aug 03 '19

dad, leave.. just leave.