[DasIch]

I very much doubt that he "dropped out" of "high school" and was able to get an apprenticeship, this is probably a bad translation.

He probably left a Gymnasium after tenth grade without getting an Abitur or didn't go to a Gymnasium after finishing Haupt- or Realschule. Unlike dropping out of high school in the US, this would still leave him with a diploma which would make getting an apprenticeship as a Fachinformatiker plausible, which is practically impossible to get without some kind of diploma.

btw. you can't just drop out of school as a minor in Germany as not attending school regularly would be illegal.