<human>: Can you give me a shortened version of the text?

Well this did happen a while ago - but who cares.

I work in an IT company a give trainings to remote customers every now and then. For one training I needed an ethernet switch. On the weekend after the training I went shopping for groceries. When I got home I cleared my rucksack from the groceries and put the switch back into the rucksack so that I wouldn't forget to return it after the weekend.

Later that weekend I was on the train home and noticed that my rucksack was a bit wet on the bottom. I thought that I had probably just put it onto some wet floor but wasn't entirely sure. So back home I wanted to check and reached into my backpack to find some cold, wet liquid everywhere. It smelled strange and acid like from the opening of my backpack and I had no clue what was happening. Did I put my rucksack into some really nasty disgusting and stinking slime without noticing? I grabbed the switch which was also covered in that slimy mass. I pulled it out to find out that I apparently forgot a plastic jar of mustard in there. Have a [look](

Well I cleaned it up as best as I could, but hiding the corrosion and the smell was simply impossible. I can't remember what I mumbled when I returned it the next Monday. The admin I borrowed the switch from is a pretty sarcastic person so I'm quite surprised he never referred to it or called me names like mustard manny. Managed to get out of it with the only damage done being that to the switch and me not being able to talk to our admin for a couple of days.

From then on I always check my rucksack before putting something from work in there.
<bot>: Managed to forget a jar of mustard in my backpack. The jar then broke and covered a switch I borrowed in the rucksack in mustard.