People notice my energy and vitality and compliment on how healthy I look and am wherever I go.

What people register as energy is usually attention. The person everyone remembers from an evening is rarely the loudest one. It's whoever asked a second question and waited for the answer.

Which is good news on a day when vigour is in short supply. Attention is cheaper than vitality and can be spent in much smaller amounts — one conversation, five minutes, then home.

Vitality, on the days you have it, is worth spending the same way. It goes further pointed at somebody than performed at a room.