At the risk of repeating something that has already been mentioned in the last 20+ pages, I'll say that the most popularly stated myth is that Schumacher made up for a lack of outright pace by being such a well rounded driver. The reality is that whilst he had solid race craft, the thing that really made him stand out was relentlessly quick outright pace. The reason that this myth exists is mainly because he drove through a period of tyre wars - where he was much more often than not on tyres that were better in race pace than qualifying pace - and then through a period of qualifying on race fuel - where he undisputedly qualified with more fuel than most of the drivers ahead of him and missed out on a lot of poles.
I think that by far Schumacher's biggest strength was his outright speed and if he had driven in almost any other era he would have broken pole records before he broke race win records. If you compare his quali pace vs his team mates I think only Senna and maybe Verstappen really have an argument to be considered better qualifiers than him over the last 40 years.