What do these mean?

[atalhe1111]

Hello, what does "a seething cauldron of raw human emotion" and "sink ones teeth into something" mean? Thanks!

 

[Teacher Dude]

The first phrase means that the person was feeling lots of very strong emotions.

BTW a cauldron is a very large cooking pot often used by witches (see Macbeth)

the second means to start doing something seriously, not just playing at it, e.g. reading a book.