This is one of the takeaways I wasn't able to formulate. Author added some disclaimers which already clarified their inexperience with the world. But I think that a.. preference for avoid human interactions, and a worldview of computer systems with no human systems are what explains why Author wasn't able to quickly adapt to this adult experience.

What sealed the deal of this interpretation to me:

"He literally writes down a phone number on a piece of paper. This is all feeling so surreal."

Why would this feel so surreal? Gauging by the dates, Author was born in around 1994, phones where definitely a thing, and phone numbers more so. My interpretation is that this guy was absolutely absorbed in computers, every social interaction occured in dms, or emails or posts, or articles. Both the 'unsophisticated' act of transmitting numbers and the need to deal with a human in real time were foreign. Without going into harsher labels like autism or antisociality, I think it's definitely the type of behaviour (described as being heads down), that is necessary to be competent enough with computers to build a hypertechnical security product over the span of almost a decade.

The point of view of the banker and how he fumbled this as well is a nice touch, illustrates the advantages of throwing a bone to your business partners. I mean even if you think of it from a non social perspective, only business, this is a supplier like any other, loyalty and gifts go a long way in general. But I guess that you don't need business acumen for a startup, you can just hyperfocus on your product and have your investors worry about the rest.