Why does my dad get cold feet right when we're about to actually transition the business?

Because the plan stops being theoretical the moment it gets close. Kris Kluver, in The Dysfunctional Family Office, watches Robert Mitchell do this a week after building his succession plan. The plan looked great on paper. The Sunday before the rollout he started feeling nervous, suggested they were moving too fast, asked whether they should reconsider. The pattern is universal among founders. The transition felt safe in the abstract. The real handoff feels like loss. Identity, daily purpose, decision authority all walk out the door at the same time, and the founder's nervous system reads it as threat. The fix isn't to slow the plan down. It's to call out the backsliding directly and proceed. Spouses and adult kids willing to name the pattern in the moment are usually what gets the founder past it.