I'm interested in hearing your stories for some much needed motivation or advice from what I've typed below.

After months or constant searching for an ancestor and with help from a couple of people on here I haven't found him.
Problem is he is down as born in a different County (Northumberland) and I just can't find any link to where I find him married with children later (Carlisle).
Just wondering if you've had a difficult person to trace and did you find him or her?
I could painstakingly go through each person with that same name (which I've started doing) and narrow it down a little by tracing each person through the censuses but find no proof or be absolutely certain I end up with the right man, do you think I'm wasting my time or should I soldier on?

I'm wondering if I've missed something, or should I try searching on different sites,
I've used IGI
Freebmd
Ancestry
GenesReunited, would another pay per view or subscription site possibly come up with something different do you think?