Averted disasters

Spent the night at Mr's, took my rucksack with kit for swimming later today - on the crowded train stuck it in the overhead shelf. Telling self several times not to forget it. At top of the escalator at Moorgate I realised I had left it there (highly susceptible to forgetting stuff at the moment). Ran back down to the train begging nobody in particular for the train not to have left. Running up the platform towards 3 train workers calling out don't let the train go - I've left my bag on it!
Why did you leave your bag?
Don't know!
What was it like?
Black rucksack
Did it have anything on it?
No. Oh yes - timberland.
Oh sorry madam, he said grinning, it's too late the train is locked, as his colleague brought the bag out of the office.
Relief!