A wall with a door

A description called “a wall, difficult and hard to get.”
Perhaps. But all walls have an invisible door or a window, cannot be seen but it is there.
Some didn’t find the door, some found it but didn’t knock, some knocked once, some knocked several times, but there were no responses. So they all went away.
Many times when the wall opened its door, nobody was there. So it closed.
One day when it opens, it happened that someone was out there, so he entered.
That’s what we call “the fate and the coincidence”, neither too early nor too late, right or wrong, just all about timing.
Those who we wait for but can never wait, are those who we pay back the time they have waited for us in our previous life;
Those who wait for us but we can never be waited, are those who we want them to pay back the time we have waited for them in our previous life;
Those who shall not be waited for, come suddenly to our door; even if they leave afterwards, we no need to wait for them anymore.
Because, once the wall opened the door and met a person, and that person’s arrival made the wall feel pleasant, the wall will increase the times it opens its door. Only some simple Opportunity Cost calculation.
A wall with a door, is difficult and hard to get, but definitely possible.