Me in the past

I’ve read some old emails of mine (2004); I couldn’t believe I used to write like that; very hard to believe; nowadays, I write a lot and the task of “I’ve written emails written in the past month” is very hard to grasp; so, in 7 years from now, I’ll have a harder task in reading things;
Still, coming back to my assertion – that was me? Very hard to believe.