How long do you keep a mower

[fk60]

had a wheel horse from 1989 till she gave up the ghost...can't remember the model number now. Old age I guess...then moved into a 2000 John Deere LX255 which I still use. Also have a bolens 1886,1972 vintage...I think this mower will out live me by a few life times...lol they just don't build them like they used to. as far as push mowers I still use an old 1980 MTD 18 inch cut...very easy to push , and use another MTD pusher that I got for free , this one maybe 6-8 years old