The 1995 top quark discovery by the CDF and D0 experiments was not unexpected, and as Nature's sixth example of a quark, its properties and interactions can often be deduced by analogy. Its large mass, in contrast, is not specified by analogy or other theoretical principles, but even this characteristic was foreshadowed by sensitive measurements of other particle systems. Mostly because of top's tremendous mass, we can predict its Standard Model properties with unprecedented precision, and still entertain hope that it plays a unique role in some greater underlying theory. With the large and exceptionally pure top samples afforded by the CDF and D0 upgrades, we are measuring many new aspects of t quark interactions, to verify that they conform to the theoretical predictions and indirect observations. I will explain several tests of predicted top properties at the Tevatron, with special focus on the first direct experimental limit on the t lifetime.