The first thing to remember about CW is that it has nothing to do with counting dots and dashes.
CW has Everything to do with rhythm and sounds. In fact Never Mention dots and dashes again, OK
For example, how many songs can you remember the words to?, several, even dozens?, and I bet
you didn't sit down and write each word/note and spend weeks trying to remember what they were
and the order in which they were sung, did you?.
It would take you forever. You learned them as a series of specific rhythmic sounds.
Each CW character has it's own unique rhythmic sound, eg 'didah' is the letter 'a' or 'A'.
It is NOT 'one dot one dash'. Say it out-loud - didah   didah   didah  didah.
Now click the play button below and listen to 'a' in cw.

Windows Media Player

It won't be long before that 'didah' sinks into your brain and you will remember it forever.
The same principal applies to the entire code, and there are only 26 letters in the alphabet!
Obviously there is a little more to it than just learning 26 letters.
There are the numbers and assorted punctuation characters that you will need,
but Learn the basic character groups first because the further you go the easier it gets.
And once you have learned the basic characters, you can progress to learning complete
words, also as a unique sound. For instance, a competent cw operator doesn't hear
'didah dahdit dahdidit as three individual characters. He automatically recognises it
as the word 'and'.

The [CW Characters] page contains the entire alphabet, numbers and some punctuation, so get stuck in.
Once you have got your brain programmed to accept individual 'rhythmic sounds' the sky is the limit.

It is worth a look through all of the cw pages and reading the text. There is some useful stuff there.