Hobbies. Stuff you enjoy doing.
I'm not retired LEO (did it for 4 years, or so, about 35 years ago) but you need fun hobbies to keep you busy/engaged.
We used to talk about, at work, how many guys retired after 30/35 years and then we'd see the announcement that they'd died from something or other within 2 or 3 years of retiring.
You've got to have a LIFE you want to live and enjoy.