I stopped working and started birding intensively in 2015. Since then I've seen quite a few new birds, and caught up with quite a few birds that were poorly seen or only seen once birds.
But there's a few that I haven't seen or haven't seen well since 2015, and really could and should see again. Here's the list with annotations (note doesn't include my two glaring life misses Storm Petrel and Quail, or either of the Hippos warblers, or birds that are no longer breeders eg Montagu's Harrier, Golden Oriole, or birds such as Chough which are in a specific location).
Leach's Petrel. Seen a couple at Canvey. Would like to see some more.
Honey Buzzard. - Clumber Park and one off Bempton back in the 80's. Nothing since
White-Tailed Eagle - Kent 1990's
Grey Phalarope - once in Keyhaven, 90's
Black Grouse. Once in the late 80's, again last year, but I'd like a decent view of both sexes.
Glaucous Gull - used to be regular in Yorkshire in the 80's, a couple down south, but not for a while
Puffin - regular at Bempton, occasional at Portland
Wryneck - Spurn, Portland at various times
Richard's Pipit - Wraysbury, late 80's early 90's.
Mealy Redpoll - various times in the 90's. Saw an Arctic at Aldborough a few years ago but the flock cleared off before I could pick out the Mealy's.
The list isn't as long as I thought it might be. But enough to be worth chasing.