I am basing this post on some experiences of my own with adult piano students, all of whom have arrived over the years with their own attitudes to/experiences of piano study. Here's a sample of scenarios:
1. The mother who learned as a teenager, whose children are at school and has decided to take up piano again, including exams.
2. The company executive who wants to do something musical and regards piano-playing as much needed rest and relaxation.
3. The senior beginner who apologises when they don't get everything 'right'.
4. The retiree who has more time to devote to enjoyable pursuits, one of which is piano playing.
5. An advanced-level pianist with already very good facility who recognises the need to 'relearn' the art of focussed practice in order to improve further.
6. The parent who is learning alongside their child/children.
Sometimes younger experiences have not been good ones...Coming back to playing and practising, they hope they will have more success. They might appreciate now what they didn't when they were at school, with the effort needed to be put in for progress to be made. The adult returner is both a challenge and a joy. Their commitment is heightened if they return after having given up earlier and having regretted it. Sometimes it's a case of 'one step forward, two steps back' as techniques require honing - hand position and scales with consistent fingering, to name two. Also, in lessons with adults, conversations crop up more naturally about harmony and harmonic progressions, structure and style. Historical anecdotes add to learning. Because adult learners usually understand music vocabulary at the outset, there are opportunities to go into more depth when discussing music, even if the playing standard is at an early stage. It's a joy to see young pupils motivated by the fact that their mum or dad practises regularly - and it rubs off! One parent I know is determined to take an exam - there's commitment and wanting to set a good example:)
The retired person may have strong attachment to music already and brings a wealth of experiences to its interpretation. I have found that conversations about the music can take the lesson in all kinds of directions - not diverting attention from what we want to achieve, but enhancing understanding of it from a student-initiated question. This might be different scales, chords, cadences and relations between keys. On the other hand, I have a student who puts immense pressure on himself to get things right, that stopping and starting is a regular feature of the lesson, with frequent self-admonishments!
"It went OK this morning in practice," they may say.
"I know - it happens to me at times," I will add. So we revert to the slow practice = quicker progress maxim, and that patience may not always make perfect, but it helps us to be kinder to ourselves. Sight reading at an easier level, as long as the student keeps going with the pulse even though' jazz notes' are thrown in, works wonders to convince such pupils what can be achieved.
The company exec. may be a confident boss in the office, but may become frustrated if progress isn't as quick as they'd hoped. Highly motivated adults often want to achieve a lot in a short space of time and they rely a lot on being able to recall the theory of music; their capacity to learn by rote (e.g. notes on the staves) might outstrip their feeling for pulse and rhythm. When the mind is willing but the fingers are less able, if spatial awareness is lacking, or coordination of left/right/up/down is slower, then frustration might set in and the student needs sensitive and varied approaches in order to overcome obstacles. After all, the understanding of music reading is very different from the physicality required to develop a sound technique - no pun intended.
I have other adult students who are playing at an advanced level, having completed their grades years ago, and are seeing music they love to play with fresh eyes and ears. They rediscover the art of deconstructing the music, examining tricky passages etc, and approach their practice with more precision and vigour.
Finally,there is a lovely short animated film which I used to refer to when teaching literacy and music in schools - The Piano by Aidan Gibbons, with music by Yann Tierson, entitled 'Comptine d'un autre ete - l'apres -midi'.
It's a poignant film about an elderly man, recalling episodes of his life while playing the piano, and reminds me very much of one or two older pupils I have had the privilege to meet. Teaching adults to play can be a very satisfying occupation indeed.