Source: personal experience. I was only physically punished a single time, but the continued emotional abuse sustained over a decade (which they learned from a guy who preached a "spare the rod"-type mentality) left me with scars that are unlikely to ever fully heal.

And in my case, I was lucky enough to remain capable of being a good student. That kind of baggage, and the expectations on top, only makes the effort to succeed in school/work an order of magnitude harder to sustain for years and years. I can only imagine how many people in my situation weren't able to accomplish what I was able to.

If for example I hadn't finished college instead, I wouldn't be surprised if certain people just blanket labeled me "lazy" like so many others, without taking into account my upbringing.

With all respect to your parents, given you were 3, I don't think it was justified. You said yourself you were imitating Looney Tunes. Who lets a 3 year old watch Looney Tunes?