51 y.o. Hands get sore after a full day of terminating, knees and back play up sometimes. That's a compound affect of 30 odd years of bulk terminating, ladder work, drilling and all the general stuff that goes with 'engineering'
You are never too old, but it helps to have some young bloods when you know there's a few days of furniture moving, floor board lifting and crawling under floors.
I have a couple of able bodied youths for such stuff
After the base learning, you will have to keep pace with new developments. So learn once, then never again is a dead philosophy- but that is good since it adds to the interest.
If you have never worked for home owners, that too is a learning curve since some are odd. Business folk (such as the telecoms work you do) know what they want, and tend to have set some rigid specific requirements.
A lot of domestic clients don't have much of a clue and they can't handle being blinded by regs and never understand why post the new flooring and final decoration our work becomes 'difficult'.
Finance might be new to you. Charging the correct daily rate or job price, getting stage payments, avoiding debates on final cost and generally handling domestic customers isn't easy.
Consider that you are going in breaking up floors, drilling holes, chopping boxes in the biggest purchase most people ever make. They are anxious and often warier due to previous problems with contractors in home.
You soon learn who not to trust- Unfortunately in London I get all customers to sign on the plans I draw up. Which creates a firm and agreed job, when it changes I expect a simple note- a variation order to protect me against denial later.
Overseas people, landlords, builders and the groups that expect bartering (due to culture) need to be handled professionally. Never take verbal instructions, because they always forget !