What? Im lost here.
read the first "misunderstanding" he used in his letter.. maybe then you will understand,, if not ask again.
Behold "I come quickly"
As for "take place"
1096. γίνομαι ginŏmai, ghin´-om-ahee; a prol. and mid. form of a prim. verb; to cause to be (“gen” -erate), i.e. (reflex.) to become (come into being), used with great latitude (lit., fig., intens., etc.):—arise, be assembled, be (-come, -fall, -have self), be brought (to pass), (be) come (to pass). continue, be divided, draw, be ended, fall, be finished, follow, be found, be fulfilled, + God forbid, grow, happen, have, be kept, be made, be married, be ordained to be, partake, pass, be performed, be published, require, seem, be showed, × soon as it was, sound, be taken, be turned, use, wax, will, would, be wrought.
Strong, J. (2009). Vol. 1: A Concise Dictionary of the Words in the Greek Testament and The Hebrew Bible (20). Bellingham, WA: Logos Bible Software.
γίνομαι
(fut γενήσομαι, aor ἐγενόμην, opt 3 sg γένοιτο, inf γενέσθαι, ptc γενόμενος, pf γέγονα and γεγένημαι, aor pass ἐγενήθην, impv 3 sg γενηθήτω, plpf 3 sg ἐγεγόνει and γεγόνει)
a come to exist: 13.80
b be: 13.3
c become: 13.48
d happen: 13.107
e move: 15.1
f belong to: 57.2
g behave: 41.1
h be in a place: 85.6
i come to be in a place: 85.7
j there was: 91.5
1. to become, i. e. to come into existence, begin to be, receive being
2. to become i. q. to come to pass. happen, of events;
3. to arise, appear in history, come upon the stage:
4. to be made, done, finished
5. to become, be made
Thayer, J. H. (1889). A Greek-English lexicon of the New Testament: Being Grimm's Wilke's Clavis Novi Testamenti (116). New York: Harper & Brothers.
As you can see, in a few greek guides. It does not always mean happen all at once, It can also mean all which i highlighted in bold. All of which could mean it begins, but the end point is unknown.
Thus the things could have started shortly. and ended later (which revelation goes from that age till the end with a new heaven and new earth.. so even though it started then all the things could continue until the end with the return of Christ, his kingdom, then the new heavens. (after judgment).