The actual error was:
ORA-00119: invalid specification for system parameter LOCAL_LISTENER
ORA-00130: invalid listener address '(ADDRESS=(PROTOCOL=TCP)(HOST=oracle)(PORT=1521))
I had finally managed to create my 11gR2 instance when I got this. So what happened?
1. Started OEL 5.5 64 bit VM
2. Logged in as user oracle
3. Opened terminal and ran . oraenv
4. sqlplus / as sysdba
5. Issued the startup command.
ORA-00130 from the docs:
So it has something to do with how I configured everything. What else did I change on the system?