Failures and mistakes, relationship friction, duty and responsibility, increased pressure and ticking clocks, ego-related conflict

Being unprepared for an important event not only has potentially devasting consequences but it can also cause the character to blame themselves for not doing what should have been done—even if that blame is unwarranted. Reasons vary for why a character may not be prepared for a work meeting, interview, presentation, speech, personal conversation, or court case. The examples that follow explore a few of these possibilities.

An emergency situation that steals the character's preparation time
Being assigned the duty last minute and having to "wing it"
Poor time management 
Taking on too much, so nothing gets done adequately
Procrastination due to an underlying fear or worry
Subconscious self-sabotage—e.g., because the character doesn't really want the promotion
Wanting to sabotage someone else who is involved
Being morally opposed to the project 
A travel or weather delay that keeps the character from important last-minute preparations
A rival tampering with the character's materials (ruining a prototype, stealing their laptop, destroying documents, etc.)
Going into the presentation drunk, hungover, very ill, or otherwise impaired
An unexpected inspection or check-in the character wasn't prepared for 

Looking unprofessional
Losing credibility 
Being embarrassed in front of peers or influential people
Letting other people down
Hurting the reputation of co-workers, the character's firm, etc.
Not getting paid for the gig because the character failed to hold up their end of the bargain
Missing out on an opportunity to step up and stand out
Losing the chance to repair a relationship or reconnect with someone