I can make you feel contented or ecstatic

Give feelings of joy, trip the light fantastic 

Conversely, offer worry, anxiety or guilt

Enough to bury your head beneath the quilt

I’ve become to know your every way

Even the pattern of your DNA

The traits and moods, sulks and broods

The finicky, picky habits to do with food

Feelings within that can make or break

Like where’s life all gone? Or am I too late?

I can change all that, make you someone new

A different approach to the things you do

Sometimes your friend or even your foe

Who am I then?  I’m your alter ego!