Another advantage is that many of the adult students have a lot to offer in the way of discussion and contribute a lot to the classes. This can work against the tutor and class though as very occasionally there are disruptive students who want to talk too much and think the whole class evolves around them! This is usually easily dealt with by a firm approach from the tutor.
Another advantage is the range of courses on offer. They range from leisure courses to postgraduate study.
The University of the Third Age is ideal for adults of around 50+ it is Adult Education on an informal level and has a tremendous range of courses on offer.
Adult education can be what you want it to be - informal or structured, academic and vocational or purely for leisure.
As opposed to formal pre- 18 education adult education is overwhelmingly voluntary and can also be a good source of social contact too.