Stop in for a cup of coffee

You guys are native English speakers and writers so i have an English question.

So this guy started a thread
i love my little router

And i notice the "i" is lower case but refers to a man. In my native language, the upper case is for referring to a man, even at the beginning of a sentence. But the lower case is always used to refer to the woman, even at the beginning of a severance because the woman is referred to like an object or thing, where as the man has a unique way of being referred to and is always an upper case when referring to himself

Either he is in error or the English language is a bit different???
‘I’ is always capitalized in English. There is no difference for masculine or feminine. He probably just got a little sloppy. I tend to do that on my phone. Especially when it ‘auto errors’ and I get annoyed with trying to correct it. I sometimes end up making other mistakes.