Blast from the past.
How fun is it if you have not seen someone for a long time and you run into an old acquaintance. A ghost from the past can really bring back many memories. A blast from the past is another way of saying this. A blast being described as a gust of wind, an explosion or a shockwave is another way to trigger your memory from something that happened in the past. It can be either a reoccurring situation or person resurfacing as a surprise, bringing back good or bad times.
Rings a bell
It is another way of referring to something you faintly know about or knew about once. It can be frustrating that you have to relearn, reeducate something you knew before. For example, parents, who need to help children with their homework. They did the same once, but boy oh boy what was it again, how did it work again? No wonder there are homework support teaching classes at primary schools nowadays.
Moving on from it rings a bell. Isn't it irritating when the knowledge is on the tip of your tongue, but you just cannot reproduce it?
This is where memory tricks come in. Everyone uses it daily. Shopping lists, little notes on the fridge, note-taking whilst studying or during a meeting. In language learning various techniques are used. One of the most famous examples is the rainbow mnemonic. Either Roy G. BIV or Richard of York gave battle in vain in English. Therefore, acronyms are not the only memory tricks you can use, others are rhymes and diagrams. The combination of visuals plus a rhyme works best. Even better if you make up your own mnemonics as everyone absorbs information in a different way.