What do you think about the practice of taking photos and keeping souvenirs? Is it a good idea, considering the need to manage, sort, and maintain them, and the fact that they often evoke feelings of nostalgia and melancholia. Should we stop taking photos at all? How do you manage this side of your life?
Take photos as others said, but more importantly if digital photos : make backups!!!
Use the software/service of your choice (I use a remote BURP server and a Nextcloud server with sync on my computer and phone), but I recommend the 3-2-1 strategy. There should be 3 copies of data, on 2 different media, with 1 copy being off-site.