Hasan Al Banna was 13 when he joined his first protest in support of the Egyptian revolution. It was 1919.
The youngster - who almost a decade later became the founder of the Muslim Brotherhood - could not have guessed that the largest protests in Egyptian history would one day take place against the movement he started.
In Egypt, Islam has usually been represented by the scholastic Azhari tradition, with which Al Banna engaged, but to which he did not belong. Today "political Islamism" usually means not a politicisation of that traditional approach to religion, but rather a politicisation of a particularly modern phenomenon.
This helps explain why the religious establishment in Egypt, and elsewhere, is wary of the Brotherhood: for them, it represents not religion in politics but the politicisation of one particular take on Islam - one they deem to be inauthentic.
This perception was a factor in the protests this week. It would be a mistake to say the protests are opposed to a role for religion in public life. Practically all Egyptians consider religion to be important on a day-to-day level, and a majority of them want religion to have a public role in the political arena. But what they regard as religion is not what they have seen from the Brotherhood.
When the Brotherhood took power, most Egyptians knew little about it, except that it was well organised, and had suffered under the former regime. The Brotherhood's base does not exceed 20 per cent of the population (and may be much less). But its voting base delivered a majority in the parliamentary elections of December 2011-January 2012.
That moment was the apex of Muslim Brotherhood support. The group regarded it as the dawn of a new era, but in truth it was the beginning of what may prove to be its utter demise, in Egypt and beyond.
Islamists in Egypt and around the region rejoiced when Mohammed Morsi was elected president a year ago, but in truth there was little to celebrate. As a symbol of the old regime, loser Ahmad Shafiq ought to have been trounced at the ballot box. Mr Morsi should have seen his narrow victory as meaning that the public was highly dubious of him.
During the 18 days of Tahrir Square in 2011, the real story was not about Hosni Mubarak but about transformation, the rejuvenation of civil society. In these past few days, the protesters have far outnumbered those of 2011, but this time there is only one demand: Morsi must go.
If the Muslim Brotherhood wants to survive, it will have to learn that the instrumentalisation of religion is not a sufficient political programme, and gives no protection against an angry populace.
For this signal to be sent within Egypt, the heart of the Arab world and the place where the Muslim Brotherhood was born, is profound.
One wonders: are Brotherhood members elsewhere now asking what went wrong in Egypt, and if the same thing could happen to them? Or do they simply see this as a conspiracy against the group?
Perhaps Brotherhood members and supporters beyond Egypt have a better vantage point than those in the country - and maybe they realise that a good part of what is happening to the Brotherhood now is a direct result of its own failures.
Only time will tell. There are other 13-year-olds protesting on Egypt's streets today. One wonders what kind of movement one of them will build tomorrow. Whatever it is, we can doubt that it will be a continuation of the Muslim Brotherhood.
Dr HA Hellyer, a non-resident fellow at the Brookings Institution and the Institute for Social Policy and Understanding, is based in Cairo
On Twitter: @hahellyer
