Harmony > Status Update

As I entered the new chapter, I noticed that the story skips to 8 years later, and Theo is apparently a 26 year old. However, in my calculation, Theo is 15 years old before this time jump, so he should be 23 years old after this jump.
Does this imply that the college scene in the previous chapter took place over 3 years? Or did I simply miscalculate the time span?