[dodgyb]

Start by getting fit. I would go and live on a beach for 3 months. Exercising in soft sand (running, volleyball, etc.) will do your body the world of good with the least risk of injury.

You will find that you will be spoilt for choice for ideas once your body is firing on all cylinders - after all the body is the temple of the mind. Ideas will come especially if you base yourself where you are likely to meet people with lots of different backgrounds.

Hydroponics has an interesting future, worth looking into if you want a mix of tech and activity.

Zappa said "You are what you is", I would add "remembering". Friends and family make the memories sweet and it's the memories that count when all is done.