How do you remember mechanics?

[Shurrikhan]

If you can get hold of a timeline and then craft your rotations around it, the muscle memory solidifies waaaay more quickly. Otherwise, it's just a sense of how many GCDs or how long relative to particular CDs each phase or interim lasts, and thinking about phases as preparing for events, rather than events alone as the time to react to them.

As far as remembering, generally, what telegraph means what, or what types of mechanics are likely to follow another, it mostly comes from an expectation of a certain level of difficulty. Normal content won't force you into anything you have to prep for, but both pair mechanics is way that causes movement, etc. If something forces you out, the next will probably force you in.

Other than that... EYE above the boss means LOOK away. INWARD arrows means stack inside. OUTWARD arrows means spread out. Etc., etc.