I left school at 16 with GCE 'O' Levels in English Literature and French, and a CSE grade 1 in Spanish. Got a royal fail in maths and a 'D' in English language.
I worked in an office for 16 years before going self-employed, and started window cleaning 2 years after that.
I don't believe qualifications mean a thing other than that it demonstrates the ability to put on paper what you remember about the subject at the time.
If people look down on us window cleaners, let them. It's honest graft for fair pay, and you don't have to spend years of your life and a king's ransom on a university education to learn to be able to do it and be successful.
John