Achieving goals being like building a bridge is a metaphor that works on a couple of levels. First, on one side of the chasm is where you are. On the other, where you want to be. Building the bridge is the planning and hard work necessary to allow you to cross from your current life to the life you choose.
On another level this metaphor works because of the process of building a bridge. Think through the steps. First, someone figures out a need for a bridge. There wasn’t a bridge there before after all. So why is a bridge necessary and why necessarily here. Making these decisions, need for a bridge and where that bridge is needed, helps clarify and solidify the goal and motivation in a person.
Second, they plan out what type of bridge is needed and the resources required. Engineering studies are done and blueprints are chosen. Is it a quick rope bridge or an 8 lane highway? Does it need to be a temporary bridge or a permanent structure? Will it take days or years to build? How much will it cost? This step helps a person start building their plan and marshaling their resources.
Third, materials are purchased, employees are hired and work begins. This is were the first actions of reaching a goal can be seen. Most of what has happened to this point is simply talking, researching and planning. Even though the first two steps are probably more important, now others can start to see work getting done.
Fourth, while the bridge is being made the work is continually inspected and modified. There are supervisors who are constantly on the job making sure the work is being done according to the blue prints. Frequently, inspectors come out to assess the work. Inspectors are also looking to ensure that reality – the depth of the river, the quality of the soil, etc. – are what were expected. If not, the plans will change to accommodate reality. On a less frequent basis, higher level employees and engineers will also monitor rate of production to completion, cost, material consumption, etc. When a person is trying to reach a goal, they should frequently monitory their progress. Are they making the progress at a rate they are happy with? Have they correctly identified all obstacles and opportunities in the first two stages or do adjustments need to be made?