Planning for my retirement

I recently had a pension review meeting with a pension expert who advised me that I had enough money in my pension plan to retire now. Even more significantly he told me that my pension payout would only increase by a very small amount if I continue working until I am 65. As a result I have decided to retire in August on my 61st birthday.

Deciding when to stop working is only part of what I need to plan. The more important part is to plan what I will do with my new free time. I have come up with the following ideas (more or less in descending order of priority):

1. Cycling: At the moment I cycle every weekend. Once I retire I will start cycling during the week as well. 
2. Lecturing: A few years ago I used to lecture to night students in Trinity College. I found this to give me a large amount of personal satisfaction. As a result I signed up to lecture in Independent College  2.5 hours per week. If this works out I  will increase my hours.
3. Night classes: My local school offers a wide range of night classes and I intend taking some of these. Last year I took gardening, guitar and pilates. In the next academic year, I have signed up for follow on classes in badminton, guitar and pilates as well as a workshop entitled ready for retirement.
4. Age Action run classes to teach basic computer literacy for older people. I intent to volunteer as a tutor. 
5. Open source: I have always wanted to see what it is like to be an active contributor to an open source project. I have not yet decided what project to pick - suggestions are more than welcome.
6. Men's shed: There is an active men's shed in Mulhuddart which is not too far from me so I plan to try it out. 
7. Book club: I am a keen reader so I think I would enjoy being part of a book club. I am sure I will find one which is close by which suits me.

I don't think I will be bored with all of these diverse activities.