In the early stages, you'll hear 'di-dah'.
Then you'll repeat it in your head and think 'di-dah' yeah, that's an A'. It's OK, you're learning. There's no time for that once you're really going at it.
In time, it'll just be an A. Subconscious. Automatic.
Then you'll find yourself hearing the dit and you'll anticipate what letters it could be. Is it an 'E', an 'I', 'A', 'W', 'J', etc. But you won't even be thinking it -the subconscious mind will take over. They'll just 'pop' into your brain.
Think about how easy it is to spell 'apple'. You've heard these letters since you were little. You just 'know' them.
With practice, you'll just 'know' them in morse. You'll associate the sound to the letter.
Then you'll be stringing them together into words. Then multiple words. Suddenly, you'll find you can almost anticipate what's coming based on the conversation. It's almost magical. Hard to describe.
You'll recognize whole words all by the sound rhythm. Like music.
And definitely mix up your practice speeds. Go too fast for a bit, and the slower code feels easier. Weird.
The hardest thing is to 'let go' of missed letters. If you dwell on the miss, you'll lose the next, or more, letters. Even with dropped letters, you'll find the mind can fill in the blanks. As long as you drop the miss and be ready for the next. Easy to describe, hard to do.
Try to drop the Farnsworth as soon as you can. That extra time between letters is for the space between words. Mixing in extra time makes it harder to know when one word stops and another starts.
Yep, it all takes time. Lots of short practice sessions. It ~will~ happen. When it does, it's such a cool feeling. Just keep building on your successes.