Picking up new hobbies, investing in them far beyond what would be considered a casual interest, then getting bored or disillusioned with the community after 6-24 months.

See

• Foam dart blasters
• yo yos
• magic the gathering (This was like 15 years)
• coin collecting
• juggling
• pocket knives
• archery
• running
• Currently working on 3D printing, though that’s been more of a means to get back into foam blasters because it’s far cheaper to print your own blasters and mod parts.