At my age flowers scare me.

In Burns’s deadpan style, the line turns a conventional symbol of cheer—flowers—into a memento mori. For someone very old, flowers can imply funerals, hospital visits, or condolences rather than romance or celebration. The joke depends on the mismatch between what flowers usually signify (life, beauty, courtship) and what they can come to signify late in life (frailty, endings). It’s also a characteristic Burns move: using self-deprecating humor about aging to defuse fear while acknowledging it, inviting the audience to laugh at mortality without denying its presence.