I was convinced that transcription forced one to write down everything one's learned. While I know that writing down these lines would benefit my notational abilities, I absolutely hate this process. I have no problem learning to play lines on my instrument. I enjoy this process, actually. After speaking with a fair amount of people about transcription, I've learned that some people write everything down; other people write down certain licks; others don't write anything out. Transcription, or, if you will, stealing lines, is a very personal process.
A few months back, I toiled away at a Horace Silver's two chorus solo on Solar, from the Miles Davis album Walkin'. The primary players on the album are Percy Heath (bass), Horace Silver (piano), and Kenny Clark (drums). I picked this solo because I enjoy it, and it's not too difficult. Within two choruses, Horace presents and develops a handful of ideas. I am particularly attracted to the ii7-V7-I7 in Eb that he played during the first chorus.
Thus far, I've taken this line through 12 keys, as-is, and know I'm trying to disassemble and put it back together. I may try to take the entire solo through all 12 keys, but I think I'm getting more out disassembling pieces of it and putting it back together.
Tonight, I may try to write out my own lines based on Horace's ii-V-I. I think I could probably spend several years on this one solo.