Like I said earlier, Therasa May is the first Prime Minister at the helm when my son came into this world although he is only one month old. I believe she is stepping down because there is a deadlock in Parliament.
I think the Brexit decision deadlock is not because of the PM. I think it is because the whole cabinet is pulling in different directions. The back benchers and cabinet ministers all have a different desired outcome. Some of them want to stop Brexit. Others want to pull out but stay in the customs union. Some MPs want a clean break from the EU without a deal. Others want a Canada style trade deal. Some like the transition deal Therasa negotiated. Some MPs think the Swiss style deal is nuts but healthy (I know that's a bad joke).
All I know is that the whole country is very much divided and parliament is no exception. A new leadership race and cabinet beacons. Rule Britannia my land of Hope and glory.