Messy I think school (or in my case university days - wanted to learn it for research purposes) can leave an entirely wrong view of learning German.
For a start off, a lot of us come out of school with a belief that there are those who are naturals at languages, and the rest of us who are crap will never get there.
In a way, this is just a general case of the British myth of the "gifted amateur who learns Sanskrit and general relativity without effort in their spare time" - see for eg Peter Whimsey in literature. It dogs the British education system - because what's actually needed to get good at anything is:
- hard work
- a willingness to make mistakes
- practice, practice and more practice
Yes there are naturals (few and far between, but I've known some) but the rest of us can learn.
As an adult, what you want to focus on building up a repertoire of stock phrases and vocabulary aimed at what you want to do. So you don't need "my postillion has been struck by lightning", but you do need "how do I find the station?" and the vocabulary to understand the answer (second left, straight on to the church on the left, take the right immediately beyond that, go across the square...), you need food, you need parts of the body, etc.
You need to be able to ask someone to repeat what they're saying, but slower. Or using simpler language.
And you need someone to practice pronunciation with a native speaker, and get tuned into listening to the language (the good news is because the stresses of German are similar to English, it's - to my ear at least - one of the easier languages to pick out individual words in).