[fecak]

It depends on how much you omit. If you omit the last 35 years and your graduation date, you show up with the expectation of a 27 year old where you are likely in your 50s. That might be considered deceptive.

Graduation dates are usually the biggest issue, as older workers tend to drop their first jobs off the resume just to save space. So if your first listed job was in 1995, people will assume you are about 42 (we assume first job around 22 years old). But if you include a graduation date of 1985, we now know you are 52. So a graduation date makes a major difference there.

You can probably overcome any personal ethical issues by calling your experience section "relevant experience" if necessary. I personally don't find that necessary, as I don't think anyone has the right to assume a resume must contain every professional activity. Resumes from foreign countries often include photos, birthdates, and marital status, which is not recommended in the US (by employers or candidates).

Don't trim off too much - you want them to value your experience. But trim just enough where you are keeping most of the relevant work without sharing unnecessary and potentially unhelpful content.