your/somebody's heart is not in it

(one's) heart isn't in it

One is not emotionally invested in something. I used to love running, but my heart just isn't in it anymore—that's why I quit the track team this year. I can tell by the way you wrote this that your heart wasn't in it. Is something distracting you?
See also: heart
Farlex Dictionary of Idioms.

your/somebody’s ˈheart is not in it

somebody does not give all their enthusiasm, interest and energy to something: He agreed to write the book for a large sum of money, but his heart wasn’t in it, and it was never finished.
See also: heart, not
Farlex Partner Idioms Dictionary
See also:
  • heart in it, have one's
  • heart not in it
  • (one's) heart isn't in it
  • have (one's) heart in (something)
  • have your heart in
  • where (one) is at
  • where (one's) head is at
  • where head is at
  • where is at
  • where someone is at