My father showed me a tree that his own father had written / drawn out about WW2 time, and gave me a copy of it. Later I got a slightly amended copy that a cousin of my father had done, modifying the original.... so far so good, interesting.....
Coming upon the trees many years later, after my own father's death, I noticed anomalies between them, and started trying to work out which was more accurate ( it was my grandfathers, his nephew had not been as good at researching as he thought he was, and had made some basic errors), and then I was helped by another cousin of my father, and she had done a much more accurate and well-documented job, recording church records, tithe roles etc., and then the husband of a friend of mine, who introduced me to using computers on it, and Ancestry, and tracked down a lot more of my paternal side, back to 1500s, as they'd been kind enough to be born, baptised, matched and buried in a small area, (with a not very usual surname) , and mostly at the same church. I'd got the idea it was quite easy to trace ancestors.
My maternal side proved far harder, the Scots were great, but indeed I've completely given up on the elusive Irish, not even certain if they really came from Northern or Southern Ireland, to be honest. Frustration. I may never know.
Then ... I got my own Ancestry account as a Christmas present from my OH, ... and then I got hooked on trying to do his side, where I started with only his grandmother's first name, and that she shared my own birthday, and had died very young, as idle comments to me by OH's mother. A couple of years later I'd got his line back to 1700s and found an interesting connection of his skills with the descendant of another line of his, who he had known, but not ever known that he was related to!
I've found some links to interesting people on the way, and gained a lot of interesting information - well, interesting to me, at least. It keeps me busy when I should be doing other things, and I'm really glad that my idle curiosity looking at two slightly different versions of hand drawn trees led me into finding out as much as I could.....
... and the road goes on.