About 10 years ago I took at trip to British Columbia from New York. In theory the trip was very simple; go to airport, get on plane, change planes in Minneapolis, land in Vancouver, get on bus, check into hotel, go skiing. Very simple steps, right?
However when I got to the airport my flight was delayed, which caused me to miss my flight out of Minneapolis, so that stopover was extended 6 miserable hours. I forgot drops for my contacts so my eyes hurt all day. My stomach hurt. I was tired. I was bored. Once I landed in Vancouver the bus to Whistler was delayed. My back hurt. My headphones were crappy. My girlfriend was sick at home and I felt bad. The bus ride was long and uncomfortable. When all was said and done I got to Whistler 15 hours later than expected.
Intellectual understanding is only one part of the journey. Our urgency, overconfidence and excitement can cause us to overlook any possible pitfalls. It can even cause us to mistake intellectual understanding for experiential confirmation of the path; a mistake that can easily plateau one's practice and send it into obscurity. Speaking from experience.
Progress along this path can happen, but it takes work. It is NOT simple.
Just my 2 pennies.