There are these aspects to the "comprehension" of this sentence. 1. It should be "I sat there ...". 2. "...if we we were filling in forms" refers to the banking practice as at the time of "thinking". The writer is puzzled why there is so much form-filling still. 3. Computerisation had been going on for some time by the time of "thinking". 4. The "why" in the sentence is a device used by the writer to couch his criticism in terms of a rhetorical question; the sentence is a criticism of bureaucracy. 5. The implication or "interpretation" is this: If the world, or bankers, are so attached to bureaucracy, form-filling and paperwork (as opposed to virtual files and electronic signature), why did we bother to computerise banking in the first place? Computerisation does not seem to have reduce laborious form-filling. 5. Simply put, the writer criticises bankers for their bureaucratic mentality - their unjustified (in her view) attachment to paperwork. 6. So the key concepts in writing here are "criticism" and "rhetorical question". The writer wishes to criticise; the "wondering" is a written device; it does not mean that "she did not understand". Every little sentence can be a rich harvest of analysis, knowledge and pleasure from such. You asked a good question.

Hello! ^^ First, remove "the": "I sat wondering.." Here "if" means like "when" or "while".

Hello! ^^ First, remove "the": "I sat wondering.." Here "if" means like "when" or "while".