How many domain names did you park and what have you spent on them?

How many domain names did you park for startup ideas in the future? ... and what have you spent on renewing those domains over the years / decades?

I will start - I have had up to 20 domains at some point, over the last 22 years ... pared them down to 3 now.

Would have spent upwards of $2000 on renewals over these years.