You could check, but the reason for the recommendation is that even healthy older people (mainly defined as over 65) have a less robust immune system, and antibodies decline faster. In addition, those of us with lung issues and/or underlying infection are at risk of becoming much sicker from Covid and other viruses.
My docs came down firmly on the side of getting the booster - side effects are milder than Covid.
PS My fully vaccinated daughter and "extra" daughter currently both have contracted Covid - they were not yet eligible for the booster, having not gotten their 2nd vaccine dose until May.

Sue