I understand the problem having to sign documents with your full names, especially when your parents don´t give you only one name, but 2 or 3 !!
On top of that, my maiden name, being a foreign name, was always hard to understand and I had to spell it.
Then, my married name - being a scottish name - was even more complicated. Many names with Mac in Scotland - some spelt separately, others joined together.
What´s in A Name?
Mercedes...look I've found a photo of you in Decathlon
You must be famous in Spain?