I saw my grandparents go through 10 years of doing all the retirement things(beach, hobbies, social hour etc) to keep them more than busy. Then they kind of did it all and just started having social hour earlier and earlier every year into their 80s. Cocktail our started about 11:30 am in the end.
I'm starting my retirement and have so many interest/subjects I want to learn so feel like I can stay pretty entertained for more than 10 years but maybe not.