For yourself: stay active, keep learning, care more about your health, and nurture your community (people with many social contacts live longer). Become wiser.
For society: give back, volunteer (in PM as Kiron says but also in the local neighborhood/NGO), present, mentor, write, and research.
I retired in 2014, then I embarked on getting my PgMP, got a diploma for company direction from IoD, was again elected to PMI's Board, started my dissertation, and, yes, earned some money with occasional engagements.