In S1:E7 of Breaking Bad, Walter and Jesse steal a barrel of methylamine. When they take them from the warehouse, they choose to carry the barrel between the two of them, which looks grueling. Is there a reason, scientific or otherwise, that they would choose to carry the barrel in that way, rather than roll it?
Their carrying the barrel rather than rolling it is to highlight their naïveté at this. It shows they have never done this before and have no idea if the logistics involved.
There is a callback to this in a later episode where they are mocked for it.
Not only did they not roll the barrel, they also walked right past the guard's cart when they did so. That cart could have carried the barrel from the loading dock to the hole in the fence where they parked their car. This shows that they really were not thinking, just panicking as they escaped.