Thank you for the explanation.
I read the story of Upatissa and Kolitha (Ven. Sariputta and Moggalana) becoming Arahant in one lifetime (by attaining stages after stages on different occasions), therefore it should be possible to attain Arahanthood in one lifetime (in this case one human jati).
If it is correct, then Ven. Sariputta and Moggalana and Ven. Angulimala must have cultivated good kamma that allows them to live in the same time as The Buddha himself which combined with good kammas for them to be born with good conditions (physical, mental, living conditions etc) which in the end allowed them to contemplate Dhamma and attain Arahanthood., therefore they all haven’t attained any stages of nibbana before, and be born many different realms (including apayas) within that waiting time.
Another interesting point also arises from this (this partly is my opinion, so please correct me if I’m wrong):
The urgent goal in this lifetime for us REALLY IS attaining Sotapanna stage, because it acts as a “brake” from this Samsaric Circle in which we have suffered for too long. This is in line with your other article (I do not remember which one).
The Arahants mentioned above must have started on the path long long ago, but for some reason hasn’t yet attained any stages, which results in a really long wait time. Unfortunately there is nobody who can accurately tell us whether we have reached any stages or not, so we should keep striving to stay on the path.
This sense of urgency has been on my mind for quite some time now, and whenever I thought of people I care about, I felt the same urgency for them, given how rare it is for any being having the chance to listen/read true Dhamma, and contemplate on it.