Timeline problem in Trainspotting 2

Spud starts writing✍️ his "story" the words he writes were "the sweat Wasa lashin ofer Sickboy" much later when he is talking to Veronica in the building site. He talks about his past. She says she thinks they are interesting and funny. She has to convince Spud to start writing✍️. He is hesitant but eventually does seem to warm to the idea.... But we have already seen him doing it. 😒😵😱