When a person finds himself in a group of other people, however small, he always "sees" them as "others" (not as "himself"). This is always the cause of whatever "strife" and "confusion" eventually ensues between them. It is also this "considering (things out there as) external" which prevents any Real "internal considering".
Although, many religions speak about "trying to see others as oneself", no one can do that (just by thinking the thought - check with yourself, if you disagree.) But what you have to eventually be ABLE to do, is precisely that - see others as yourself. That is, to realize that genetically, cellularly, electro-chemically, you ARE others. And, but for 'fate' or 'accident', you could "have been" them.
You could BE anybody.
The arbitrary boundary between "you" and "not-you" is a totally, mind-constructed, film-of-thought. This is the film of, what is variously called, "sleep", "ignorance", "ordinariness", "normality", "reality". It is this film which interacts with the world. Always and Everywhere.
If you can still see yourself, in a mirror, you're externally considering.
Internally consider all that you see, and realize it IS you -considering.