Because I travel frequently to Africa?
Because my account goes relatively quiet whenever I'm abroad, then wakes up again when I'm back in the UK?
Because I have bank accounts in France and Togo?
Because most of my income is in the form of donations given through a UK registered charity?
Because I've been paying in a lot of cash from car boot sale fund-raising events recently?
Because I used my debit card at an Arab restaurant in Jerusalem last week?
Who knows? No idea at all. Your guess is as good as mine.