After having this earlier retirement dream now for several years I can honestly say one of the harder lessons I’ve had to accept is reality doesn’t always match the plan. This really isn’t a bad thing and given the huge about of things that happen in a life you should be amazed that your reality even looks close to your plan.
Let me say you should still make a plan, but I would caution about not getting too attached to it. Life just happens and sometimes takes your lovely calculations and shoves a knife into the middle of the page. As I’ve often found to date kids can introduce so many more variables to your decision making process.
Perhaps a better way of thinking about a plan is a rough map to where you are going on a road trip. You should look at your goal and decide a few reasonable sign posts of progress and work towards them. So once you leave your current path towards your goal you can revise your plan to see if you can still get where you want on time. If not, would it kill you to be a little late as long as you still get there?
Perhaps the most painful realization about reality not looking like the plan is the fact you might have to give up your original goal as being possible. This sucks, but sometimes it is required. It also provides an interesting opportunity for self reflection. Did you really want that goal or just think you did? Or was the goal represent something larger? If it is representing something larger can you get that in a different way than your first goal you had to give up? Would getting another goal make me more happy? Keep poking away at that grey matter called your brain until you start to get ideas for other goals. Life evolves why shouldn’t you as you get older?
The flip side to this is you could reach your goals faster than you thought on a different path. Life is strange sometimes and occasional it can be really good to you. Take your opportunity where you can and keep your map in pencil: you never know when you will need to plot a new course.