We're all human (not you, search engine bot. Go away!), and humans are rational within their constraints. Initially I was going to title this post "Respect Legacy", but it occurred to me that it applies equally to the present.
Let me start with an anecdote. I had a very talented project manager at one point. We worked in a really big project within higher education, and by the time I joined the project was already a bunch of years old even though it wasn't in production yet. Needless to say there was a lot of legacy code already. Since the project had gone through a few different phases and the technology landscape had changed radically during those years people would often stumbled over old code and ask why it had been written in that way to begin with.
The answer from said project manager was always the same:
We must assume that we, and our predecessors, did the best they could under the circumstances and constraints they had. Maybe there wasn't time, maybe it was the best solution available at the time. We don't need to know the reason.
This has resonated with me. In the past year or so I've started applying it to situations in my private life as well. We've all made mistakes, and we still make them, and it's easy to judge and hard to forgive. I've especially had a difficulty forgiving myself for past mistakes, particularly the very big ones.
Lately I've come to realise that even though I've done some stupid shit I've always done my best under the circumstances that applied. The same applies to other people. Although it's sometimes hard (or even very hard) it's imperative that we view the actions of others through a lens of kindness first. We should always assume that people do their best; we may not always succeed but we do try.
-- CC0 Björn Wärmedal