Wednesday Writing Prompt #3

You know the score by now, so here is the opening phrase:

The wall felt sticky beneath my palm

Okay, so what have we got? Don't jump to immediate conclusions, or run with your first impressions. Think it through and think round the obvious:

What sort of wall? 
Where is this wall?
...felt sticky - note the 'felt'. Why not looked?
...sticky with what? Think smell, taste, temperature - use the