What Motivates People to Cheat on Taxes?

For most countries, April 15 is the deadline for filing income tax returns. Although proper compliance is required by law, there are people who accidentally or purposefully under report their tax liability, underpay their tax reported, or fail entirely to file a return. For those who knowingly try to cheat, what motivates them to do so?

Suggestion:

People who knowingly try to cheat, probably do so to save themselves a lot of money.

People who cheat accidentally or negligently, probably do so because the tax laws are very complex, they didn't obtain help with calculating their taxes, or they figured that the IRS would never notice that they didn't file a return.

Every year, we try to simplify our financial life, so that when tax time rolls around we can do a good job with it, and it won't be a major hassle. But it always is, just the same.