My very 1st beer 50 years ago, we called it Shitz for obvious reasons.
Yeah, that was about the time that the brewery started messing with the recipe. They tried to cut corners to pad the bottom line and it really impaired the quality of their beer. Your experience was common. From Wikipedia:
By 1967, the company's president and chairman was August Uihlein's grandson,
Robert Uihlein Jr. Faced with a desire to meet large volume demands while also cutting the cost of production, the brewing process for Schlitz's flagship Schlitz beer was changed in the early 1970s. The primary changes involved using corn syrup to replace some of the malted barley, adding a silica gel to prevent the product from forming a haze, using high-temperature
fermentation instead of the traditional method, and also substituted less-expensive extracts rather than traditional ingredients even building a new brewery specifically designed to use the process in
Baldwinsville, New York. The reformulated product resulted in a beer that not only lost much of the flavor and consistency of the traditional formula, but also spoiled more quickly, rapidly losing public appeal.
During the reformulating period of the early 1970s, the original Schlitz beer formula was lost and never included in any of the subsequent sales of the company. Through research of documents and interviews with former Schlitz brewmasters and taste-testers, Pabst was able to reconstruct the 1960s classic formula. The new Schlitz beer, along with a new television advertising campaign, was officially introduced in 2008.