Willis made 19 appearances for Connacht this season but with 14 of those coming off the bench, he said his enjoyment of the game was weaning in the last few months.
“There are all sorts of reasons for making the decision to retire. I love the game of rugby but I got so bloody frustrated not playing every week,” admitted Willis.
“It is just the way I am; it does my head in when I am not getting a game. I play rugby for the fun of it and the fun was going out of the game for me.”
Willis spent the last two seasons with Ulster, where he made 15 appearances, and had two years with his native Leinster prior to that where he played a dozen games. He plans to move home to Wicklow and work in the family nursing home business.
“We have one nursing home in Bray and have another opening in August so it is going to be pretty busy.
“It will be a massive change for me. I suppose it really sunk in after the Munster game last week but it is the right decision for me.
“I will be going back to playing with Greystones and will train their U20s as well as doing some training in a local school. This should bring me back to the type of rugby that I enjoy. It was time to be honest with myself and take the plunge. It would have been easy to roll in and pick up a pay cheque but that is not me.”
But as well as losing the love of the game, Willis is well aware of the pitfalls of professional sport.
“Sometime you need some luck and maybe I didn’t have that with injuries. I have broken around 15 bones, have had double vision in one eye after an operation and my back has been giving me problems.
“And when you look at all the retirements from the pro game lately it makes you think. What will it be like in 10 or 15 years? The game is played at a phenomenal intensity with massive men bashing off each other. It is a massively rewarding game to play but is unbelievably attritional.
“I have absolutely no regrets, but it is time for me to give another side of life a shot.”