The road completely shuts down because people cannot pass that accident. The same thing will happen to you if you lose your one source of income. Your life will essentially come to a halt if you are not prepared to deal with a loss of income from your one job.
Now imagine your career trajectory is a two lane highway. Each lane of the highway represents a different source of income. When an accident happens in one lane, I can still manage to get by in life - albeit slower than normal - and move pass the accident. This allows me to still make a living even though one source of income has been reduced or lost.
On top of protecting yourself in the event of an accident, when the road is clear and open, you can drive a little faster than you could drive on that one lane highway. Essentially, a two lane career trajectory offers more opportunities in a shorter amount of time.
Let's take this another step forward. Imagine a three lane interstate highway. Speeds on this highway can reach some of the fastest in the country. So too will your career advance if you learn to add more lanes to the highway of your career.
When an accident happens in one of these lanes - i.e. a loss or decrease in income - I can easily get by with little inconvenience because I am not relying on only one source of income.
An obstacle that drivers often come across on the highway is construction. Road builders and civil engineers continuously add lanes to overcrowded highways to make traffic flow more smoothly in the future. While there certainly are temporary headaches to contend with, ultimately the project has benefits for everyone involved.
This is how you should look at the training and education you give yourself in your career. While taking some time away from work or family to focus on getting an advanced degree or pursuing additional licensing may result in a temporary roadblock, the long term benefits will certainly outweigh the short term inconvenience. Focus more of your attention on highway construction now to benefit more in the future.
A note of caution for everyone trying to add lanes to their highway. Make sure the lanes are all going the same direction. Drivers don't like it when engineers are resurfacing roads because each lane is different than the other during the resurfacing process. Don't look to be an events manager, a car salesman, and a biotech engineer. Clients and customers will be confused by what services you really focus on. Stick to careers that have a similar or complimentary trajectory so your customers will understand the added value you can provide.
Finally, when building your super highway that is your career, you will notice an interesting phenomenon. As you add more and more complimentary lanes to your highway, more lanes will be built and added for you. The more and better projects you work on, the more people will want to be involved with the work that you do. This will ultimately allow you to make more connections and add even more lanes to your highway.
While the saying, "don't put all your eggs in one basket" is a mantra that should be highly regarded in the world of finances and savings, it is time you start applying that ideal to the process of making money in the first place.