Was Jesus wrong in his prediction concerning the end of the world?

It has been said that this prophecy of Jesus was mistaken,

Truly, I say to you, this generation will not pass away until all these things take place. (Matthew 24:34)

I do not wish to delve into a complete analysis of the Olivet discourse here, yet there are a few comments that need to be made.

The quote comes up when Jesus is leaving the temple having chastised the scribes and warned against them.

Jesus left the temple and was going away, when his disciples came to point out to him the buildings of the temple. But he answered them, “You see all these, do you not? Truly, I say to you, there will not be left here one stone upon another that will not be thrown down.” (Matthew 24:1-2)

Later the disciples responded.

As he sat on the Mount of Olives, the disciples came to him privately, saying, “Tell us, when will these things be, and what will be the sign of your coming and of the end of the age?” (Matthew 24:3)

Note that the disciples are asking 2 and possibly 3 questions here, even though they may have thought they were asking about a single event. Jesus had said that the stones of the temple would thrown down. The disciples asked:

1. when will these things be?
2. what will be the sign of your coming?
3. [what will be the sign] of the end of the age?

Questions 2 and 3 may be the same question though they need not be. In the subsequent discussion called the Olivet Discourse Jesus answers these questions but as there is 2 and possibly 3 questions, his answers address different components.

In his answer he warns them; he says things will be terrible; he says there will be deception; he says his return will be obvious. The initial question was in response to Jesus' comment about the temple stones, thus part of the answer refers to the Fall of Jerusalem, though it need not all be about the events 4 decades hence. If we read the rest of Jesus quote it reads,

So also, when you see all these things, you know that he is near, at the very gates. Truly, I say to you, this generation will not pass away until all these things take place. Heaven and earth will pass away, but my words will not pass away. But concerning that day and hour no one knows, not even the angels of heaven, nor the Son, but the Father only. (Matthew 24:33-36)

Jesus says,

1. Recognise the time of the end at the time of the end
2. This generation will not pass away until all these things take place
3. No one knows the time

And he says all this together. So understanding his meaning must take this into consideration. What might "This generation will not pass away" mean then? I can think of at least 3 possibilities.

It may refer to the temple question. This generation will not pass away until the temple will not have one stone left upon another.

It may refer to the time of the end. The people living at the time of the end are to recognise that they live at the time of the end because of the signs and they can know that when these signs are all being completed the end will definitely arrive within this generation.

It may be better translated,

This generation will not pass away until all these things begin to take place.

In which case the things Jesus is talking about will commence within a generation.