Or book's', or website...or someones blog?

I've been at this for 20 yrs. Read everything at first i could get my hands on before the internet.
I even, and kinda adorable, used a gifted large format plant press for my tomato leaves years ago. (did i really have that much time!?). I was growing many varieties and still do.
I never did narrow it down to what works well in my climate. I still start seeds, saved seeds, traded seeds, of about 75 varieties. Maybe 6 are t&t must haves every year.

Last year this time, i accidentally dumped two start trays back behind my starting shelf. I was surprised i could identify many by their leaves, some by their size. Obviously not perfect as i had many varieties to sort.

Yet, it happened again last night when potting up a few transfers. (not a dumping or tripping). New ones i'm trying and missed some labeling at one point. I could easily narrow it down via some neighboring ones by size and leaf.

Just want to study why. Any suggestions?
-i have been looking around for a while this past cold winter...