in regards to your subject line question....Overactive Imagination? ....only you and your treatment provider ie a medical doctor, your therapist, or your psychiatrist can say whether this is an over active imagination for you...

what I can tell you is that I know both normal and not so normal, / creative and not so creative/ not so active and over active/...types of people and imaginations..

for some people doing this is completely normal and for others it isnt. the best thing I can tell you is contact your treatment providers if this continues to bother you, they can help you figure out if this is normal for you or if its considered an over active imagination or if its other things..