Osmosis?

I was on the bus today minding my own business when a small Asian lady of the middle-aged fanny pack and oversized sun visor variety decided to sit down beside me. No problem. I moved my backpack off the seat and then as the bus began to move she continued to stand in the aisle.

She fumbled around with her fanny pack and soon produced a small spray bottle and cloth. She then proceeded to wipe down and disinfect the entire seat before sitting. She was very thorough. For a moment I thought she was going to disinfect me too.

What I don't understand is how concerned she was about germs on the seat when she didn't seem to flinch at the thought of touching the handrails while getting into the bus. Seems to me that it would be easier to get sick by touching germs and then rubbing your nose than it would be by sitting on them. Maybe she absorbs bacteria by butt osmosis.