Defect-free software does not exist.
At the time the Sendmail program had a very poor reputation with respect to...
When I write software I know that it will fail either due to my own mistake...
I left school at 16 but I wish I'd gone to university - I think I would have studied English literature. I had a knack for that. But I don't think you have the kind of wisdom at 16 to make that decision.