True, but for me the real problem is actually identifying that ideal amount of planning for some project.
It's easy in hindsight to say something was over reaching or not enough planning was done, but not always that simple prior to starting a project.
Ideal planning vigor and scope seems super context sensitive to me and even with experience I often feel I get it wrong.
Hindsight is a crucial part of making sure you don't make the same mistakes. Don't worry, you'll have plenty of opportunities to make brand new mistakes.
- boss: Yeah, don't spend too much time on planning it will be at best inaccaurate
- me: ok; I make a plan and, well, there are known unknows
- later on, my boss: why have you those unknowns ? don't you think it's obvious that unknowns are a problem and that we can't show our customer we have unknowns because we're-professionals-we-know-what-we-do ?
- me: err... well...
Long term plans are only inaccurate or wrong if they're over reaching. Plans, like every other part of a project, have to be able to change and grow throughout implementation. It's not long-term planning that is the issue, it's the stagnation of overbearing plans.