IPv6 Abbreviations - Abbreviating rules

Just as I thought I was mastering IPv6 understanding, the result is FAIL.
I got the removal of 0's the wrong way round.  Take note, unlike I did.

"When abbreviating an IPv6 address
you can remove the leading 0's from within a single octet. 
You cannot remove the trailing 0's.
:: can be used only once in the address
to collapse octets of 0's."

2233:0000:2222:0011:0000:0000:0000:0001
can become:
2233:0:2222:11::1