I'm not sure why. It's not my best language, nor my newest, but I just like speaking it, and I have lots of Brazilian friends and chances to practice. If your Spanish level is high, listening comprehension comes very quickly, but it takes some time to separate it in your head so you don't trip over your tongue. For example, ver and vir (sp: venir) are just as irregular as in Spanish, but in different ways. Viram is "they saw," but vieram is "they came." Vs vieron and vinieron. It will mess up your brain at first.