Thais often smile in uncomfortable of difficult situations. They think that smiling is especially important then. It keep relationships between people strong. There are many different kinds of smiles for difficult situations. One of them means "I don't agree with you" (yim thak thaan). Another one means "I know the situation is bad, but there's no point in crying about it now" (yim yae-yae). Then there's the smile then means "I know I owe you money , but I don't have it " (yim haeng). There's even a smile for jokes that aren't funny (fuen yim)!