Of course the "ultimate way" is relative to your skill level. At the end stages of musical development though I agree simply reading through a piece will reveal the way to play it and this only comes since you have a huge experience base with music, a large range of pieces/styles, an understanding of how music is crafted and expressed. If you have strong reading skills then not knowing notes or rhythm is somewhat an obsolete problem. Of course there are pieces which demand incredibly high technical skill and perhaps they might not interest even the best technicians because of the time it takes to learn, we after all only have limited time on this earth.
I have attached. it's the strike through icon with [ s ] and [ / s ]
If you are having trouble playing a work until you it memorized (per your statements), something basic is grossly lacking.Repition and physical memory as a means to memorization is inefficient and yeilds incomplete memorization most of the time. It is the most likely to fail you or escape in performance or the momment some aspect of performance condition is different or changes from practice and study conditon.Having a concious idea of where you are in a piece's structure or form helps you with a mental map of knowing where you are going (ie in a sonata or concerto, being in a development area or transition to a recapitulation)Firm understanding of harmony, or tonal centers where there is one is important too.You should know how a piece and melody should sound, that is leave out a voice, hum or sing it in isolation, of while playing Test my teacher uses to humble me and expose reliance on muscle memory and show me not truly fully memorized.1. Play left hand by itself by memory2. Plat righ hand by itself by memory3. Place right on on piano desk lyre or fallboard lip, play both hands together so lh plays piano keyboard, then rh plays the fingers but by pressing the hard flat surface vs keys, then reverse4 truly humble yourself, play the left hand part with right hand, transpose up octave(s) as needes but reproduce the part for lh with right, and flip it, play right hand part down low with left hand. I almost always crash and burn early with this evaluation in lessons , but once you really know it and can do this, you are showing evidence of in depth knowledge of the piece and very little risk of"Having to start over" or go back to a section. Or skip foward to a memory station if you blip out while play. you know the piece so well.Above level of learing cannot be rushed, but progress there is faster if you study the score, do some basic analysis and listening, etc. Repitition has a place but it should be part and integrated with deep understanding study.So the faster you fully learn and understand the piece, the fastsr and more fully you will learn it, and you are learning music faster, more completely, then i see that as an "ultimate" way to learn music, to use your word, which in this context i am not sure is the best descriptor or word choice, as ultimate is really "last or , final", but i would set out to learn by this method preferebtially, not as a last choice or resort
The mechanistic aspect of needing to memorize a piece before it can actually be played is what bothers me.