MySQL, FULLTEXT in phpmyadmin

I've created a FULLTEXT index for the TEXT column myColumn my MySQL database in phpmyadmin.

1. The index for this column is reporting a cardinality of 50581, exactly one third the number of rows in my table (i.e. 151743). Why is that? And does it matter? (I have also three TEXT columns, if that matters.)

2. I ask because my MATCH searches seem to be开发者_C百科 missing hits. For example, if I do SELECT * FROM myTable WHERE MATCH(myColumn) AGAINST ('dude') ORDER BY id LIMIT 30 returns hits whereas SELECT * FROM myTable WHERE MATCH(myColumn) AGAINST ('want') ORDER BY id LIMIT 30 returns none (when say ...LIKE '%want%'... returns lots). Why is that?