I seem to hear this a lot, but there's probably like 10 commands (maybe a few more if you want to be fancy with copy-paste). Note: great if you like nano however!

For those that are interested, this will get you 90% there:

exit without saving> :q!

exit with saving> :wq

beginning of line> 0

end of line and edit (enter insert mode)> shift-a

delete line> dd

insert mode> i

stop insert mode> ESC

undo> u

show line numbers> :set number

go to line number (e.g line 5)> :5