I always want to tell my newly married friends that things will change, not to judge other couples by the standards of what they feel like right now.
But when you speak of the difficulties in relationships, people assume you're not happy. Nobody can go 20 years in a relationship without some ups and downs.
So I just say hold on! Like most rides it can be fun, scary, and at times it lags because some unforeseen glitch has you sitting for 20 minutes in the same place stagnant.