get ahead of oneself

get ahead of (oneself)

To plan or become overly excited for a possible future event. A: "I love this house, I can't wait to live here!" B: "Whoa, the sellers still have to accept your offer, so don't get ahead of yourself." I think she's getting ahead of herself here—I mean, they've only been dating a few weeks, and she's practically planning their wedding.
See also: ahead, get, of
Farlex Dictionary of Idioms.

get ahead of oneself

Fig. [for someone] to do or say something sooner than it ought to be done so that the proper explanation or preparations have not been made. I have to stick to my notes or I will get ahead of myself in my lecture. When he bought a new little bicycle before the baby was born, he was getting ahead of himself.
See also: ahead, get, of
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • get ahead of (oneself)
  • hold horses
  • hold one’s horses
  • hold one's horses
  • hold your horses
  • Hold your horses!
  • double buffalo
  • take it easy
  • take it/things easy
  • drop a bombshell, to