I’ve done 5 10 day long retreats and just eye-balling how many people were still there at the end, I’d say at least 95% managed to stay till the end.
I also know two people with ADHD who say they struggle a lot with discipline, yet they both managed to meditate 6+ hours everyday on said retreats.
My only data is personal anecdotes like this.
Here is what I’ve written down in my H.E.A.L summary re. positive experiences. Maybe helpful for some:
A positive experience could be anything that feels pleasant, it is useful, and that you want to cultivate in your mind.
Some examples:
feeling good about yourself
being proud of something you’ve achieved
feelings of being liked, loved, loving, grateful
feeling safe, calm, relaxed, joyful
getting a hug, compliment, etc.
A positive experience could be:
intellectual understandings, Intentions, Skills, Moods, Abilities, Attitudes, Feelings
The key is to get something like a Felt Sense, some emotion, some feeling in your body, etc, so you can move beyond just some intellectual understanding towards an implicit emotional understanding in the following steps.
You can look for good facts in:
Your immediate situation
Current or recent events
Ongoing stable conditions
Yourself
The past
The future
The lives of others
The good in bad situations
Your imagination (things that have not yet happened or even things that will never happen)
Produce Good Facts: e.g. be kind and caring to others; share about good facts with others.