There are situations when you feel that 95-98% of your goal is achievable, at the same time remaining 2% seems very difficult to achieve. You are a planner & have sufficient time to plan, what will you do.
Good thing is to anticipate such situations well in advance. So, you have time on your side.
Now, choice is to be happy with 98% & focus on same only to reduce risk of achieving 98% or focus on 2% also.
It's about how you think & aim. Most will focus only on 98% but few will try & focus first on 2% as that's what is going to make the difference. Yes, simultaneously the work on 98% starts.
Though this may not be applicable in all situations but yes this is applicable in some important situations.