I currently have 1500+ open tabs on my smartphone.

The tab counter shows ":D", but I knew the number because I once accidentally closed all tabs and quickly restored them, so the browser told me that I had closed ~1500 tabs.

Let's not talk about the number of tabs and windows on my computer :D

I'm keeping them because I remember stumbling upon some interesting links that are hard to find again, and which require further action (like buying a book), so I'm planning to return to them in the future.