I saw someone walking into my driveway but no one’s there

So I was just inside my house then I looked outside my window, I heard a motorcycle driving in and parking in my driveway thinking my brother’s come home as he drives a motorcycle.

Then, I saw what appeared to be a man dressed in all black with a black helmet on walking by the window. I thought okay that’s my brother but then he didn’t come inside the house.

So I went outside to see who’s actually there then there was no trace of any motorcycle or anyone being outside. This is late in the afternoon so it’s not dark or anything. I swear I physically saw the man in black with the helmet on walking by.

I thought it was an intruder but nobody was there. But I SAW that man and it’s driving me crazy.

I don’t know what I just saw.