Spanking it at the bank

Whenever I'm at the bank, either queued up for the bank machine or maybe to just make a withdrawal or deposit with a banker I get the strong urge to masturbate.I normally have to leave the queue of people to use the closest public toilet to make a personal deposit. I'm not sure what gives me such an extreme urge, it could be the thought of depositing my money into the bank? Is this normal???