Sexual and and current affairs references are the hardest to get - euphemisms change, for example In spite of this I do get a lot. Some are pretty obvious ("your tongue in my tail", for example) I am sure I miss many. Some productions try harder to make things obvious than others. Then there is all the stuff you do get so the comedies are still pretty funny overall.

I think Your TV analogy is probably pretty accurate. Kids also do not get a lot of sexual references in TV comedy too!