I frequently lose my passion for video games, but never really lose my passion for gaming. If I'm not playing video games, I'm getting my fix through cards games (the CCG variety and/or poker), board games, tabletop wargames, or pencil-and-paper role-playing games. Even if I'm not regularly or actively playing, I'm still tangentially engaged, building/testing decks or painting miniatures or building terrain or crafting campaign storylines and world building. One of the things that helps me always come back to video games is having those other outlets because my joy and passion for one inevitable stokes the fire for the others. Playing a lot of tabletop Mordheim got me into Vermintide in a big way, which make me craft a Warhammer-influenced deck the next time I played Magic: The Gathering. Playing a bunch of space-themed games on PC made me want to check out Starfinder and run a campaign for my friends, which eventually led to a couple of them getting those PC games and us playing together.

Actually, friends can be a pretty good means of restoring passion/keeping it alive. I find that having other people excited to play and enjoying games can go a long way toward getting me excited to be playing. Maybe I'm easily influenced that way or something, but enthusiasm can be infectious. Unfortunately, I'm of an age where most of my friends are now married and/or have children, so it's hard to schedule playing stuff together, especially games that involved major time commitments. So, while the OP said they don't watch videos of other people playing games, I might actually recommend people try that when they need that extra motivation. Again, seeing someone else having a lot of fun with a game can spark your desire to get in on it. Even if you don't stick with that particular game, just the experience of playing something might be all it takes to hook you and draw you back into the hobby.

Lastly: exercise. If you have a predominantly sedentary lifestyle, where you already do a lot of sitting (especially in front of a monitor), you need to get up and move around, or get outside and take a walk. (I find early evening walks are great for that, though your mileage may vary depending on your local weather/temperatures and the area where you live, not to mention your schedule.) Sitting around at school/work and in your free time is a breeding ground for ennui and depression, both of which are detrimental, not only to your well-being but your motivation and ability to derive pleasure from activities you'd otherwise enjoy. Treadmills, ellipticals, rowing machines, stationary bikes...all great places to get some exercise (doesn't have to be an intense workout, just some physical activity) and just let your mind wander and indulge your imagination a bit. You might have trains of thought or whimsical fantasies that spark a desire to play a particular game, old or new. Or, as ulfrinn suggested, you may come up with an idea for your own game and that gets you excited, either to try and figure out how to make your idea a reality (whether through developing from the ground up or as a mod for a game you already enjoy) or maybe just to play some games just to see how their systems work as a means to further develop your ideas.

Beyond that, all you can do is wait for the passion to return on its own. Maybe it will take a few years. Maybe it won't ever come back. It's fine if it doesn't. Sometimes you outgrow hobbies. If it doesn't excite you anymore, if you don't enjoy doing it, why try to force it? Enjoy your memories of the fun you had but you should feel free to move on.

I have an old Atari 2600 (that's almost certainly suffered moisture damage or somesuch from being in storage), a Sega Genesis, and an original PS1. Though, I didn't specifically hold onto them for sentimental reasons so much as I just don't think I'd get much for them (if they even still work).

I really enjoyed the first game - despite its ultra-simplistic art style, it was fiendishly addictive - but the switch to third person, sadly, killed my interest in the sequel.

LAN parties.

Some damn good calls with Vanquish, Sleeping Dogs and Dragon's Dogma. I'd buy sequels to all of those.

I was always kind of disappointed there wasn't a followup to Syndicate. That always felt like a game that didn't do as well as it deserved in sales, because so few people seemed to give it a chance, and that's a shame.

Without a campaign, there's no reason for me to spend money on Black Ops.

I might pick up Battlefield V. It sounds like they're doing some really cool and interesting things with that game, and I've always preferred Battlefield's multiplayer to Call of Duty, but..it's EA. If there's one company I'd trust to completely f*** up what should be a great game, it's EA. (Though, Activision does seem to be gaining on them.)

I'd say my gaming sessions average 4-6 hours. Though, there are those rare occasions where I lose an entire day to a game, where I started playing in the early evening and, next thing I know, it's daylight outside, or I started playing on a Saturday morning and don't stop until I realize I've skipped lunch and dinner and that's why I feel like I'm starving, or I've spent so much time playing a single game that, when I sleep, my dreams are made up of that same gameplay. Thankfully, there have been some wonderful advancements in controller ergonomics and I've not suffered from hand cramps or "Nintendo thumb" since the days of the NES.

I remember spending a lot of time just driving around the city, at night, listening to The Journey. There was just something about that...it was like a quiet moment in a Michael Mann film. I think that was my favorite part of the entire experience.

It's one of those games, like Deadlight, I always meant to check out when it was dirt cheap but, because of the generic name, never remember to look for whenever there's a sale.

Metal Gear Rising Revengeance and occasionally still poking at Star Traders: Frontiers.

Also, Battlefield 3. I know I'm late to the party on this, but...what the hell happened? Coming off almost 200 hours of Battlefield Bad Company 2, this is just unbearable.