I am fluent in English and Polish and used to be fluent in German, as I spent about 2 and a half years in the German school system.
These days I can understand most German if it's spoken slowly, but if I turn on a German TV station or movie, it's a bit more challenging. Usually I'm able to figure out the meaning by filling in the blanks and paying attention to the intonation and the way things are said and the context.. but some of what's said does elude me. Back in 2012 I was in Peru and met a French girl who spoke German and didn't mind using it to communicate with me so we could both practice. That ended up being a horrible idea, as she would just talk and talk and talk and I was always wayyy behind trying to understand everything.. and when it came time to respond, I had trouble finding the words for what I wanted to say, and could not help it but stick to the same words over and over.. my vocabulary is very lacking. And that was a decade ago. I bet that if I moved to Germany for a month or two, a lot of it would come back. When I hear German being spoken, it sounds very warm and familiar to me.
My Polish is getting a bit rusty too, but I am still functionally fluent in it. I can easily hold a conversation in Polish with my parents and other relatives. Polish is also a somewhat flexible language, so if I forget a Polish word it's very easy to slide in a modified English word without skipping a beat. For whatever reason I'm pretty good at Polish grammar and spelling, so when I decide to sit down and write things out, it's pretty easy for me.. although my vocabulary is not really that impressive either. We left Poland when I was in grade 3, so a lot of the recent pop cultural references and changes to the language have not been on my radar... there's a lot new words - thankfully (??) a lot of them are straight imports from English... So it's a mixed bag, but if I moved back to Poland today I would easily be able to interact with everyone. If I moved back to Germany right now, it would probably take me a month or two to get back up to speed, and at first I would have slow interactions with people, pausing to remember a lot more words than I would in Polish.
I have learned some French, but the level of French education in Canada is not very high (from my personal experience), so I have basically learned "jack squat". In grade 9 I got the highest mark in French class, but that's just because the communist education system and my own kind of personality made it easy for me to memorize things. So.. For French tests.. I just memorized all the verbs and how to conjugate them duh. Super easy to get all 90% and some 100%s. At the end of the year I knew exactly zero French, but had the highest mark in the class. My counsellor convinced me to take the advanced version of French for next year, which was an incredibly spectacular failure. On my first test, on which I big time cheated on, I got just barely 30%. I basically didn't know anything, as the test was written in a language I could not speak at all - French. There was this girl sitting beside me who I got along with, so I just copied off a lot of her answers.. filling in some of my own, so it wouldn't be obvious. Well, it turns out she didn't know any French either, because her answers were mostly wrong. I quit out of that class the day after getting my test back. I will also never forget how we had to go around the class and say something about ourselves (in French) on the first day, so I just memorized parts of what other people said, and ended up yammering out something about "Mon ami jouer le basketball" or something stupid like that. So yeah, I wish I knew more French, but I know no French. It's written on everything here, so I have picked some up, but if you said French stuff to me it would be all Greek to me, aside from the short popular phrases everybody knows. If I look at written French I can figure out some of the meaning, as there are many familiar words, and I have learned some of the other ones over time due to cereal box, etc. presence.